What is the circle of confusion?

The circle of confusion is the largest blur spot still perceived as sharp. It scales with sensor size, so this tool uses a standard value per format — about 0.029 mm for full frame and 0.019 mm for APS-C.

Why does the far limit show infinity?

When the subject distance reaches or exceeds the hyperfocal distance, the far limit of acceptable sharpness extends to infinity, so the depth of field becomes effectively unlimited beyond the near limit.

How does aperture affect depth of field?

A smaller aperture (larger f-number, like f/16) increases the hyperfocal distance denominator differently and deepens the depth of field, keeping more in focus. A wider aperture (smaller f-number, like f/1.8) shrinks depth of field for a blurred background.

Why does sensor size change the result?

Smaller sensors use a smaller circle of confusion, so for the same framing they tend to show more apparent depth of field. The tool picks the standard circle of confusion for your chosen format automatically.

Is depth of field split evenly in front and behind the subject?

No. At normal distances roughly one-third of the depth of field falls in front of the subject and two-thirds behind it. The tool reports the in-front and behind distances separately so you can see the split.

What is hyperfocal distance?

It is the focus distance at which depth of field extends from half that distance all the way to infinity. Focusing at the hyperfocal distance maximises the depth of field for a given lens and aperture — ideal for landscapes.

Depth of Field Calculator

Q: Is anything uploaded?

No — all calculations happen entirely in your browser and nothing is sent anywhere.

Depth of field calculator

Work out exactly how much of your scene will be in focus. Enter your sensor format, focal length, aperture and subject distance, and the tool returns the near limit, far limit, total depth of field and the hyperfocal distance. It is built for photographers planning landscapes, portraits and product shots.

How it works

The calculation uses the standard optics of depth of field. First it finds the hyperfocal distance:

H = f² ÷ (N · c) + f

where f is focal length (mm), N is the f-number and c is the circle of confusion chosen for your sensor (about 0.029 mm for full frame, 0.019 mm for APS-C). From H and the subject distance s it computes the near and far limits:

near = s(H − f) ÷ (H + s − 2f) far = s(H − f) ÷ (H − s)

When s reaches or exceeds H, the far limit becomes infinity. Total depth of field is far − near.

Example

Full frame, 50 mm lens at f/2.8, subject at 3 m (c = 0.029 mm):

Hyperfocal H ≈ 50² ÷ (2.8 × 0.029) + 50 ≈ 30.8 m
Near limit ≈ 2.74 m, far limit ≈ 3.32 m
Total depth of field ≈ 0.58 m (about 26 cm in front, 32 cm behind)

Setting	Value
Focal length	50 mm
Aperture	f/2.8
Subject distance	3 m
Total DoF	~0.58 m

All calculations happen entirely in your browser and nothing is sent anywhere.