Aperture Area Calculator
Light-gathering area of a circular aperture from diameter or f-number and focal length.
Compare Your Options And Get Clear Answers
Light-gathering area of a circular aperture from diameter or f-number and focal length.
Aperture Area Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
Enter Values
Fill in each field with your own numbers.
Calculate
Results update as you change the inputs.
Review
Read the breakdown and the explanation.
Adjust
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Aperture Quick Guide
Typical values for reference.
| Focal mm | f-number | f-number | Area mm2 |
|---|---|---|---|
| 50 | 1.4 | 1.4 | 1,001.8 mm2 |
| 50 | 1.8 | 1.8 | 606.0 mm2 |
| 50 | 2.8 | 2.8 | 250.4 mm2 |
| 50 | 5.6 | 5.6 | 62.6 mm2 |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Aperture Area Calculator FAQ
Answers to common questions about this calculator.
The opening size that lets light through the lens.
It is focal length divided by diameter.
Diameter = focal length / f-number; area = pi d^2 / 4.
It is an estimate based on the inputs you enter. Check real quotes, labels or official guidance for important decisions.