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ND Filter Exposure Calculator
New exposure time after adding a neutral density filter.
1/s
stops
How it works
Each stop of ND doubles the exposure time, so new time = metered time × 2^stops. A 10-stop filter is also called ND1000 or ND 3.0, because 2^10 is about 1,000 and its optical density is about 3.0. Enter 125 for 1/125 s, or 0.5 for a 2 second base exposure. Real filters can add a color cast and reciprocity effects on film. Example: A metered 1/125 s exposure with a 10-stop ND filter becomes 8.2 s (8.2 seconds).
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.