CalculatorCast

Depth of Field Calculator

Find near/far sharpness limits and hyperfocal distance for your shot.

Introduction

Depth of Field Calculator — Find near/far sharpness limits and hyperfocal distance for your shot. Enter Focal Length, Aperture (f-number), Subject Distance, Circle of Confusion to get an instant, accurate result.

Formula

Hyperfocal distance H = f²/(N·c) + f, where f is focal length, N is the f-number, and c is the circle of confusion (all in mm). Near limit = H·s/(H+(s−f)); far limit = H·s/(H−(s−f)), where s is subject distance — far limit becomes infinity once s ≥ H.

Step-by-step

  1. Enter the Focal Length.
  2. Enter the Aperture (f-number).
  3. Enter the Subject Distance.
  4. Enter the Circle of Confusion.
  5. Click Calculate to see your result instantly.

Real-world example

Example: With Focal Length = 50 mm, Aperture (f-number) = 8, Subject Distance = 5 m, Circle of Confusion = 0.03 mm, the Depth of Field Calculator gives Hyperfocal M: 10.4667, Near Limit M: 3.3946, Far Limit M: 9.4864.

Frequently Asked Questions

Why does the far limit sometimes show infinity?
Once your subject distance is at or beyond the hyperfocal distance, everything from roughly half that distance to infinity is acceptably sharp, so the far limit has no finite value.
How does aperture affect depth of field?
A smaller aperture (larger f-number) reduces the hyperfocal distance and widens depth of field — more of the scene, in front of and behind the focus point, appears sharp.
What is the circle of confusion and why does it matter?
It's the largest blur spot the eye still perceives as a sharp point on a normal-sized print viewed at a normal distance; a smaller CoC value (common for higher-resolution or smaller sensors) narrows the depth of field the formula returns.
What inputs does the Depth of Field Calculator need?
You'll need to provide: Focal Length, Aperture (f-number), Subject Distance, Circle of Confusion. All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.
How accurate is the Depth of Field Calculator?
The Depth of Field Calculator applies the formula exactly as calculated — Hyperfocal distance H = f²/(N·c) + f, where f is focal length, N is the f-number, and c is the circle of confusion (all in mm). Near limit = H·s/(H+(s−f)); far limit = H·s/(H−(s−f)), where s is subject distance — far limit becomes infinity once s ≥ H. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.
Is the Depth of Field Calculator free to use?
Yes, the Depth of Field Calculator is completely free, requires no signup, and runs instantly in your browser.

About the Depth of Field Calculator

The Depth of Field Calculator uses a real, verifiable formula — Hyperfocal distance H = f²/(N·c) + f, where f is focal length, N is the f-number, and c is the circle of confusion (all in mm). Near limit = H·s/(H+(s−f)); far limit = H·s/(H−(s−f)), where s is subject distance — far limit becomes infinity once s ≥ H. — so results are accurate every time, not an approximation.