Depth of Field (DOF) Calculator

Calculate near and far depth-of-field limits and the hyperfocal distance from focal length, aperture, focus distance, and sensor size.

Result

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How to use this calculator

Enter the lens focal length in mm and the aperture f-number.
Enter the focus (subject) distance in metres.
Select your sensor format so the right circle of confusion is used.
Read the near and far limits, total DOF, and hyperfocal distance.

About this calculator

Depth of field (DOF) is the range of distances in a photo that appear acceptably sharp. It depends on four things: the lens focal length, the aperture, how far away you focus, and the sensor format — which sets the "circle of confusion," the largest blur spot still perceived as a point. This calculator computes the near and far limits of sharpness, the total depth of field, and the hyperfocal distance: the focus distance at which everything from half that distance to infinity is sharp. Wider apertures (smaller f-numbers), longer lenses, and closer subjects all shrink the depth of field; stopping down, using a shorter lens, or focusing farther away expands it. When your focus distance reaches or exceeds the hyperfocal distance, the far limit extends to infinity.

How it works — the formula

Hyperfocal  H = f²/(N·c) + f
Near limit   = H·s / (H + (s − f))
Far limit    = H·s / (H − (s − f))   [∞ if s ≥ H]
(f, c in mm; s = focus distance)

The hyperfocal distance sets the scale of sharpness for a given focal length, aperture, and circle of confusion. Near and far limits are derived from it and the focus distance; the far limit diverges to infinity once you focus at or beyond the hyperfocal distance.

Source: Wikipedia — Depth of field (formulae & CoC)

Worked examples

Example 1

50 mm, f/8, 3 m, full frame

Inputs:: focal=50, aperture=8, distance=3, sensor=ff
Output:: H≈10.8 m, near 2.36 m, far 4.12 m, DOF≈1.77 m

Example 2

24 mm, f/11, 2 m, full frame

Inputs:: focal=24, aperture=11, distance=2, sensor=ff
Output:: H≈1.83 m; 2 m ≥ H → far = ∞

Example 3

85 mm, f/1.8, 1.5 m, full frame

Inputs:: focal=85, aperture=1.8, distance=1.5, sensor=ff
Output:: DOF ≈ 0.03 m (very shallow)

Limitations

Circle of confusion is a convention (sensor diagonal ÷ 1500); your sharpness standard may differ.
Diffraction softening at small apertures is not modelled.
Assumes the focus distance is measured to the subject, not the sensor plane offset.

DOF is perceptual; treat the limits as guidance, not a hard sharp/blurred boundary.

Frequently asked

What is depth of field?+

Depth of field is the zone, from a near limit to a far limit, in which objects look acceptably sharp in the final image. Outside that zone, detail blurs progressively. It is a perceptual range, defined relative to a circle of confusion that depends on sensor size and viewing conditions.

What is the hyperfocal distance?+

The hyperfocal distance is the closest focus distance at which the far limit of depth of field reaches infinity. Focusing there maximises DOF: everything from half the hyperfocal distance out to infinity is acceptably sharp. It is widely used in landscape photography.

What is the circle of confusion?+

It is the largest blur spot on the sensor that still looks like a sharp point in the final print or screen view. Smaller sensors use a smaller circle of confusion (roughly the sensor diagonal ÷ 1500), which is why this calculator asks for your format — full frame uses about 0.029 mm, APS-C about 0.019 mm.

How does aperture affect depth of field?+

A smaller aperture (larger f-number, e.g. f/16) increases depth of field; a wider aperture (smaller f-number, e.g. f/1.8) shrinks it for a blurred background. Each stop down roughly proportionally extends the hyperfocal-based limits, though diffraction softens the whole image at very small apertures.

Why is depth of field not symmetric around the subject?+

For typical distances, more of the in-focus zone falls behind the subject than in front — often roughly one-third in front and two-thirds behind, though the exact split varies with distance. This calculator shows the front and rear portions separately.

Does a crop sensor change depth of field?+

Yes. For the same framing and aperture, a smaller sensor has greater depth of field because it uses a shorter actual focal length and a smaller circle of confusion. Selecting the correct format here accounts for the circle-of-confusion part of that effect.