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Exposure Stops Difference Calculator

Compare two exposure settings and see the difference in stops.

Setting A aperture

Setting A shutter (1 ÷ value)

1/s

Setting A ISO

Setting B aperture

Setting B shutter (1 ÷ value)

1/s

Setting B ISO

How it works

Brightness is proportional to ISO × time ÷ N². The stop difference is log2 of the ratio between the two settings. A value of +1 means B records twice as much light as A, and −1 means half. Use it to check whether two combinations really match before you change a setting. Example: Moving from f/8 at 1/125 s to f/4 at 1/250 s gives 1 stops of change. Result: B is brighter than A.

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.