All calculators

Percentage Calculator

Find X percent of any number.

Percentage Change Calculator

Increase or decrease between two values.

Average Calculator

Mean, median, and sum of a list of numbers.

Pythagorean Theorem Calculator

Hypotenuse and area of a right triangle.

Temperature Converter

Celsius, Fahrenheit, and Kelvin at once.

Length Converter

Meters, kilometers, miles, feet, and more.

Weight Converter

Kilograms, grams, pounds, and ounces.

Age Calculator

Your exact age in years, months, and days.

Tip Calculator

Split the bill and tip between friends.

Days Between Dates Calculator

Count the days between two dates.

Mortgage Calculator

Monthly mortgage payment from price, down payment, and rate.

Savings Goal Calculator

How much to save each month to reach a goal.

Inflation Calculator

What prices or savings will be worth after years of inflation.

VAT Calculator

Add or remove VAT from a price.

Hourly to Salary Calculator

Turn an hourly wage into daily, weekly, monthly, and yearly pay.

Break-Even Calculator

Units and revenue needed to cover your costs.

Credit Card Payoff Calculator

How long it takes to pay off a balance.

Calorie Calculator

Daily calories to maintain, lose, or gain weight.

Body Fat Calculator

Body fat percentage using the U.S. Navy method.

Heart Rate Zones Calculator

Training heart rate zones using the Karvonen method.

Pregnancy Due Date Calculator

Estimated due date from the first day of your last period.

Circle Calculator

Area, circumference, and diameter from the radius.

Rectangle Calculator

Area, perimeter, and diagonal of a rectangle.

Quadratic Equation Solver

Real roots of ax² + bx + c = 0.

GCD and LCM Calculator

Greatest common divisor and least common multiple.

Standard Deviation Calculator

Mean, variance, and standard deviation of a data set.

Ratio and Proportion Calculator

Solve a : b = c : x.

Speed Converter

Convert km/h, m/s, mph, and knots.

Volume Converter

Liters, milliliters, gallons, cups, and fluid ounces (US).

Area Converter

Square meters, square feet, acres, and hectares.

Data Storage Converter

Bytes, KB, MB, GB, and TB (decimal units).

Fuel Economy Calculator

Fuel consumption in L/100 km, km/L, and miles per gallon.

Date Calculator

Add or subtract days from a date.

Time Duration Calculator

Hours and minutes between two times.

Fuel Cost Calculator

Fuel needed and cost for a trip.

Unit Price Calculator

Compare two products by price per unit.

Countdown Calculator

Days remaining until a date.

Electricity Cost Calculator

What a device costs to run.

GPA Calculator

Weighted GPA from grade points and credits.

Final Grade Calculator

The score you need on the final exam.

Test Score Percentage Calculator

Percentage and letter grade from points.

Reading Time Calculator

Estimated reading and speaking time.

Paint Calculator

Paint needed to cover the walls of a room.

Concrete Calculator

Concrete volume for a slab.

Tile Calculator

Number of square tiles for a floor.

Markup Calculator

Selling price, profit, and margin from cost and markup.

Commission Calculator

Commission earned and total pay from sales.

Invoice Total Calculator

Invoice total with discount, tax, and shipping.

Payback Period Calculator

How long an investment takes to earn its money back.

CAGR Calculator

Compound annual growth rate between two values.

Rule of 72 Calculator

Estimate how many years it takes money to double.

Retirement Savings Calculator

Projected savings at retirement with monthly deposits.

Ohm's Law Calculator

Current and power from voltage and resistance.

Kinetic Energy Calculator

Energy and momentum of a moving object.

Density Calculator

Density from mass and volume.

Free Fall Calculator

Fall time and impact speed from a given height.

Half-Life Calculator

Amount of a substance left after a given time.

Recipe Scaler

Scale an ingredient amount up or down for more or fewer servings.

Cooking Measurement Converter

Convert cups, spoons, milliliters, and fluid ounces.

Coffee Ratio Calculator

Coffee grounds needed for the water you brew with.

Car Loan Calculator

Monthly car payment, interest, and total cost.

Car Depreciation Calculator

Estimated car value after several years.

EV Charging Cost Calculator

Cost to charge an electric car between two battery levels.

Running Pace Calculator

Pace per kilometer and speed from distance and time.

One-Rep Max Calculator

Estimate your maximum single lift from a multi-rep set.

Calories Burned Calculator

Calories burned by common activities.

Protein Intake Calculator

Daily protein target for your activity level.

Macro Calculator

Grams of protein, carbs, and fat from calories and split.

Waist-to-Hip Ratio Calculator

Body fat distribution from waist and hip size.

Triangle Area Calculator

Area and perimeter from three side lengths.

Combinations and Permutations Calculator

Count ways to choose or arrange items.

Median, Mode and Range Calculator

Median, mode, range, and sum of a list of numbers.

Sphere Calculator

Volume and surface area from the radius.

Split Bill Calculator

Divide a bill and tip evenly between people.

Working Days Calculator

Count weekdays between two dates, both included.

Download Time Calculator

How long a file takes to download at a given internet speed.

Weighted Grade Calculator

Overall grade from scores and their weights.

Typing Speed Calculator

Words per minute and accuracy from a typing test.

Flooring Calculator

Flooring area and boxes needed, including waste.

Gravel and Mulch Calculator

Volume and weight of gravel for an area.

Time Converter

Convert seconds, minutes, hours, days, weeks, and years.

Pressure Converter

Convert Pa, kPa, bar, psi, atm, and mmHg.

Energy Converter

Convert joules, calories, watt-hours, and kilowatt-hours.

Dividend Yield Calculator

Dividend yield and yearly dividend income from a stock.

Stock Profit Calculator

Net profit, return, and break-even price after trading fees.

Debt-to-Income Ratio Calculator

See what share of your income goes to debt each month.

Customer Lifetime Value Calculator

Estimate how much a customer is worth over the full relationship.

ROAS Calculator

Return on ad spend, profit after ads, and break-even ROAS.

Lean Body Mass Calculator

Estimate lean mass and fat mass with the Boer formula.

Sleep Cycle Calculator

Bedtimes that match 90-minute sleep cycles for your wake-up time.

Percentage Difference Calculator

Percent difference between two values, regardless of order.

Prime Number Checker

Check if a number is prime and find the next prime.

Arithmetic Sequence Calculator

Nth term and sum of an arithmetic sequence.

Angle Converter

Convert degrees, radians, gradians, and turns.

Roman Numeral Converter

Turn a number from 1 to 3999 into Roman numerals.

Birthday Countdown Calculator

Days left until your next birthday and the age you will turn.

Pizza Size Value Calculator

Which pizza gives you more for your money?

Study Time Planner

Daily study hours needed to finish your material before an exam.

Brick Calculator

Number of bricks for a wall, including mortar joints and waste.

Stair Calculator

Number of steps, exact riser height, and total run for a staircase.

Wavelength and Frequency Calculator

Convert a wave frequency to wavelength using the speed of light.

Molarity Calculator

Solution concentration from mass, molar mass, and volume.

Projectile Motion Calculator

Range, peak height, and flight time of a launched object.

Oven Temperature Converter

Celsius to Fahrenheit, gas mark, and fan oven setting.

Rice to Water Ratio Calculator

How much water to cook your rice.

Tire Size Calculator

Overall diameter, sidewall height, and circumference from a tire code.

Car Lease Calculator

Monthly lease payment from price, residual value, term, and rate.

Steps to Distance Calculator

Convert steps to kilometers, miles, time, and calories.

Number Base Converter

Convert a decimal number to binary, octal, and hexadecimal.

Aspect Ratio Calculator

Simplest aspect ratio and the matching height for a new width.

Password Strength Calculator

Estimate password entropy from its length and character set.

Trip Budget Calculator

Total trip cost from lodging, food, transport, activities, and flights.

Currency Converter (Manual Rate)

Convert money with your own exchange rate and fee.

APR to APY Calculator

Convert a nominal APR into the effective annual yield.

Net Present Value (NPV) Calculator

Discount future cash flows to see if an investment is worth it.

Emergency Fund Calculator

Find how much cash cushion you need and how long it takes to build.

Net Worth Calculator

Add up assets and debts to see your net worth.

Extra Loan Payment Calculator

See how much interest and time extra monthly payments save.

Rent Affordability Calculator

Estimate how much rent fits your income.

Customer Acquisition Cost Calculator

Find your CAC and compare it with customer lifetime value.

Churn Rate Calculator

Measure customer churn, retention, and expected lifetime.

Inventory Turnover Calculator

See how many times you sell through stock each year.

Economic Order Quantity Calculator

Find the order size that minimizes ordering and holding costs.

Body Surface Area Calculator

Estimate BSA with the Mosteller, DuBois, and Haycock formulas.

Waist-to-Height Ratio Calculator

Check central body fat with a simple waist-to-height ratio.

Weight Loss Timeline Calculator

Estimate how long it takes to reach your goal weight.

Mean Arterial Pressure Calculator

Calculate MAP and pulse pressure from blood pressure readings.

Factorial Calculator

Calculate n! with digit count and trailing zeros.

Permutations and Combinations Calculator

Count arrangements and selections of r items from n.

Slope and Distance Calculator

Distance, slope, midpoint, and line equation from two points.

Ratio Simplifier

Reduce a ratio of two whole numbers to its simplest form.

Logarithm Calculator

Log of any number in any base, plus ln, log10, and log2.

Area Converter

Convert between square meters, acres, hectares, square feet, and more.

Volume Converter

Convert liters, gallons, cups, ounces, cubic feet, and more.

Speed Converter

Convert km/h, mph, m/s, knots, feet per second, and Mach.

Power Converter

Convert watts, kilowatts, horsepower, and BTU per hour.

Leap Year Checker

Check if a year is a leap year and find the next one.

Day of the Week Calculator

Find the weekday, day of year, and week number for any date.

Dog Age Calculator

Convert dog years to human years by size.

Word Counter

Count words, characters, sentences, and reading time.

Attendance Percentage Calculator

Track attendance and how many classes you can still miss.

Exam Time Planner

Work out how many minutes you can spend per question.

Drywall Calculator

Estimate drywall sheets and joint compound for a room.

Roof Area and Shingles Calculator

Estimate roof surface area, squares, and shingle bundles from pitch.

Wallpaper Calculator

Find how many rolls of wallpaper you need.

Ideal Gas Law Calculator

Solve PV = nRT for pressure, volume, temperature, or moles.

pH Calculator

Convert between pH, pOH, H+ and OH- concentration.

Specific Heat Calculator

Heat needed to warm or cool a material: Q = m × c × ΔT.

Meat Per Person Calculator

How much meat to buy for a meal or party.

Engine Displacement Calculator

Engine size in cc, liters, and cubic inches from bore and stroke.

Race Time Predictor

Predict 5K, 10K, half marathon, and marathon times from one result.

PX to REM Converter

Convert pixels to rem, em, points, and percent for CSS.

Video File Size Calculator

Estimate file size from bitrate and duration.

Future Value of Regular Savings Calculator

See what regular deposits grow to with compound interest.

Present Value Calculator

Find what a future sum is worth in today's money.

Loan Affordability Calculator

Work out the largest loan a monthly payment can support.

Average Cost Basis Calculator

Average your purchase price across several buys and see profit or loss.

Overtime Pay Calculator

Calculate total pay including overtime hours and multiplier.

Ovulation & Fertile Window Calculator

Estimate your ovulation day and fertile window from your cycle.

Ponderal Index Calculator

Body proportion index based on weight divided by height cubed.

Creatinine Clearance Calculator

Estimate kidney function using the Cockcroft-Gault formula.

Fraction Calculator

Add, subtract, multiply, or divide two fractions.

Z-Score Calculator

Find how many standard deviations a value is from the mean.

Nth Root Calculator

Find square roots, cube roots, and any other root.

Cylinder & Cone Calculator

Volume and surface area for a cylinder and a cone of the same size.

Force Converter

Convert newtons, pound-force, kilogram-force, and more.

Torque Converter

Convert newton-metres, pound-feet, pound-inches, and kgf-m.

Frequency Converter

Convert hertz, kilohertz, megahertz, gigahertz, and RPM.

Year Progress Calculator

See how much of the year has passed and how much is left.

Carpool Savings Calculator

Compare commute costs per person when you share the ride.

Subscription Cost Calculator

Add up what your monthly and yearly subscriptions really cost.

Course Study Load Calculator

Estimate weekly study hours from your credit load.

Fence Materials Calculator

Count posts, rails, and pickets for a fence run.

Mulch & Soil Volume Calculator

Cubic yards and bags needed to cover a garden bed.

Employee Turnover Rate Calculator

Measure how many staff leave relative to your average headcount.

Ecommerce Conversion Rate Calculator

Turn visits and orders into conversion rate and revenue metrics.

Newton's Second Law (F = ma) Calculator

Force from mass and acceleration, with speed and distance after a time.

Dilution Calculator (C1V1 = C2V2)

Find how much stock solution you need for a target concentration.

Bread Hydration Calculator

Total hydration, salt, and starter percentages for sourdough.

Cost per Mile / km Calculator

Total ownership cost of a vehicle per distance unit driven.

VO2 Max Calculator (Cooper Test)

Estimate aerobic fitness from a 12 minute run.

CIDR / Subnet Host Calculator

Subnet mask and usable host count for a CIDR prefix.

Road Trip Planner

Driving time with rest stops, plus fuel cost for the trip.

Solar System Size Calculator

Estimate the solar array size and number of panels your home needs.

Solar Panel Output Calculator

Daily, monthly, and yearly energy from a set of solar panels.

Solar Payback Period Calculator

How many years a solar system takes to pay for itself.

Solar Charge Controller Size Calculator

Pick the right charge controller current for your panels and battery bank.

Battery Runtime Calculator

How long a battery can power a load.

Battery Bank Size Calculator

Size a battery bank for off-grid or backup power.

Battery Charge Time Calculator

Estimate how long a battery takes to charge.

Power Bank Charges Calculator

How many times a power bank can charge your phone.

LED Bulb Savings Calculator

Savings from replacing old bulbs with LEDs.

Standby Power Cost Calculator

What devices cost you while idle or on standby.

Appliance Upgrade Savings Calculator

Will a more efficient appliance pay for itself?

Daily Energy Load Calculator

Add up the daily energy use of several appliances.

Electrical Power Calculator

Real, apparent, and reactive power from volts and amps.

Three-Phase Power Calculator

Power in kW and kVA for a three-phase supply.

kVA to kW Calculator

Convert kVA to kW and current for single or three-phase supplies.

Power Factor Correction Calculator

Capacitor size needed to improve power factor.

Voltage Drop Calculator

Voltage drop and power loss along a cable.

Wire Size Calculator

Minimum cable cross-section for an allowed voltage drop.

Generator Size Calculator

Choose a generator size from running and starting loads.

Series and Parallel Resistor Calculator

Total resistance of resistors in series and in parallel.

LED Resistor Calculator

Series resistor value for an LED.

Capacitor Energy Calculator

Energy and charge stored in a capacitor.

Transformer Turns Ratio Calculator

Secondary voltage and currents from a transformer turns ratio.

Pump Power Calculator

Hydraulic and shaft power needed to pump water.

Wind Turbine Power Calculator

Estimate power from a wind turbine.

Building Heat Loss Calculator

Heat loss through walls, windows, or a roof, and the heating cost.

Air Conditioner BTU Calculator

Cooling capacity needed for a room.

Air Conditioner Running Cost Calculator

Monthly electricity cost of running an air conditioner.

Water Heater Cost Calculator

Energy and cost to heat your daily hot water.

Electricity Carbon Footprint Calculator

CO₂ emissions from your electricity use.

Raised Bed Soil Calculator

Soil volume and number of bags needed to fill a raised bed.

Plant Spacing Calculator

How many plants fit in a bed at a given spacing.

Lawn Seed Calculator

How much grass seed you need for a new or overseeded lawn.

Fertilizer Application Calculator

How much fertilizer to spread to hit a nitrogen target.

Garden Watering Calculator

Weekly water volume for a garden bed or lawn.

Rainwater Harvesting Calculator

Water you can collect from a roof and the barrels to store it.

Seed Starting Calculator

How many seeds to sow to end up with the plants you want.

Vegetable Garden Size Calculator

How big a vegetable garden you need to feed your household.

Pot Soil Volume Calculator

Potting mix needed to fill round planters and containers.

Growing Degree Days Calculator

Heat accumulation used to time planting and harvest.

Jet Lag Recovery Calculator

Estimate how many days your body needs to adjust to a new time zone.

Flight Time Calculator

Estimate flight duration from distance and cruising speed.

RAID Capacity Calculator

Usable storage and fault tolerance for common RAID levels.

Car Ownership Cost Calculator

Yearly and monthly cost of running a car, fuel included.

Pizza Dough Calculator

Flour, water, salt, and yeast for any number of pizzas.

Recipe Nutrition per Serving Calculator

Calories and macros per serving from the recipe totals.

Body Fat Calculator (Navy Method)

Estimate body fat percentage from tape measurements.

Exposure Value (EV) Calculator

Convert aperture, shutter speed, and ISO into an exposure value.

Depth of Field Calculator

Near and far limits of acceptable sharpness for any lens setup.

Hyperfocal Distance Calculator

Find the focus distance that keeps everything to infinity sharp.

Crop Factor Calculator

Crop factor and full-frame equivalent focal length and aperture.

Field of View Calculator

Horizontal, vertical, and diagonal angle of view for a lens and sensor.

Reciprocal Rule Shutter Speed Calculator

Slowest shutter speed you can hand-hold without blur.

ND Filter Exposure Calculator

New exposure time after adding a neutral density filter.

Exposure Stops Difference Calculator

Compare two exposure settings and see the difference in stops.

Equivalent Exposure Calculator

New shutter speed that keeps exposure the same after changing aperture or ISO.

Print Size from Pixels Calculator

Largest print you can make from an image at a chosen quality.

Resolution Needed for Print Calculator

Pixels and megapixels required for a print of a given size.

Pixel Pitch and Diffraction Calculator

Pixel size and the aperture where diffraction starts to soften images.

Photo Storage Calculator

How many photos fit on a memory card and how long it lasts.

Video Recording Time Calculator

How many hours of video fit on a card at a given bitrate.

Slow Motion Calculator

Slow-down factor and final clip length from frame rates.

Shutter Angle Calculator

Convert between shutter angle, frame rate, and shutter speed.

Time-Lapse Calculator

Frames, clip length, and storage for a time-lapse sequence.

Flash Guide Number Calculator

Aperture needed for correct flash exposure at a given distance.

Light Falloff Calculator

How much light you lose when you move a light farther away.

Macro Magnification Calculator

Reproduction ratio, effective aperture, and exposure loss for close-ups.

Shooting Distance Calculator

How far to stand to fit your subject in the frame.

Drone Ground Sampling Distance Calculator

Ground resolution and image footprint for drone mapping.

Panorama Shots Calculator

Number of photos for a full 360° panorama with overlap.

Astrophotography NPF Rule Calculator

Longest exposure before stars turn into trails.

Sunny 16 Rule Calculator

Estimate exposure outdoors without a light meter.

Print Viewing Distance Calculator

Best viewing distance for a print and the resolution it really needs.

Crop Zoom Resolution Calculator

Resolution left after cropping in to simulate a longer lens.

Film Reciprocity Failure Calculator

Corrected exposure time for long film exposures.

Film Cost per Frame Calculator

True cost of shooting film including development and scanning.

Photographer Hourly Rate Calculator

Hourly rate you need to charge to reach your income goal.

Dog Daily Calorie Calculator

Daily calories and cups of food for a dog by weight and life stage.

Cat Daily Calorie Calculator

Daily calories and cups of food for a cat by weight and life stage.

Pet Food Cost Calculator

Daily, monthly, and yearly food cost plus how long a bag lasts.

Pet Weight Loss Timeline Calculator

How many weeks a pet needs to reach its target weight at a safe weekly pace.

Puppy Adult Weight Calculator

Estimate how much a puppy will weigh when fully grown.

Cat Age in Human Years Calculator

Convert your cat's age to human years and see its life stage.

Pet Daily Water Intake Calculator

How much water a dog or cat needs each day by weight.

Aquarium Volume Calculator

Water volume of a rectangular tank in liters and gallons.

Aquarium Stocking Calculator

Rough number of small fish a tank can hold using the inch-per-gallon rule.

Aquarium Water Change Calculator

How much water to replace to bring nitrate down to your target.

Aquarium Heater Size Calculator

Heater wattage needed to warm a tank from room temperature.

Aquarium Treatment Dose Calculator

Scale a water conditioner or medication dose to your tank volume.

Aquarium Filter Flow Rate Calculator

Pump or filter flow you need for the tank size and turnover you want.

Aquarium Weight Calculator

Total loaded weight of a tank and the load it puts on the floor.

Pet Monthly Cost Calculator

Monthly, yearly, and lifetime cost of owning a pet.

Pet Insurance Break-Even Calculator

Compare your yearly cost with and without pet insurance.

Pet Treat Allowance Calculator

How many treats fit in your pet's daily calorie budget.

Dog Crate Size Calculator

Minimum crate length and height for your dog.

Pet Boarding Cost Calculator

Total cost of boarding one or more pets, with a multi-pet discount.

Horse Hay Needs Calculator

Daily, monthly, and yearly hay for one or more horses.

Rental Yield Calculator

Gross and net rental yield from price, rent, and expenses.

Cap Rate Calculator

Capitalization rate and implied value of an income property.

Cash-on-Cash Return Calculator

Yearly cash flow as a percentage of the cash you put into a rental.

Rental Property Cash Flow Calculator

Monthly and yearly cash flow after every cost of a rental.

Gross Rent Multiplier Calculator

GRM of a rental and its value at the market multiplier.

Rent-to-Price Ratio Calculator (1% Rule)

Check a rental against the 1% and 2% rules of thumb.

DSCR Calculator (Debt Service Coverage Ratio)

Debt service coverage ratio and the largest loan your income supports.

Down Payment Calculator

Down payment, closing costs, and total cash needed to buy a home.

Closing Costs Calculator

Estimate buyer closing costs from the loan and the price.

Property Tax Calculator

Annual and monthly property tax from value, rate, and exemptions.

Home Appreciation Calculator

Future home value and gain at a steady yearly growth rate.

Home Equity and LTV Calculator

Equity, loan-to-value ratio, and how much you could borrow against it.

Price per Square Meter / Foot Calculator

Price per square meter and square foot, compared with the market.

House Flip Profit Calculator

Profit, ROI, and the 70% rule maximum offer for a flip.

Home Sale Net Proceeds Calculator

Cash you walk away with after commission, closing costs, and your mortgage.

Real Estate Commission Calculator

Total commission, the buyer and listing sides, and an agent payout after the split.

Mortgage Points Break-Even Calculator

Whether buying discount points pays off before you sell or refinance.

Refinance Break-Even Calculator

Monthly savings and months to recover refinance costs.

Prorated Rent Calculator

Rent due for a partial month from a move-in date.