Depth of Field Calculator

Depth of field (DoF) is the zone in front of and behind your focus point that appears acceptably sharp. It is controlled by four things: aperture, focal length, distance to the subject, and sensor size. A wide aperture like f/1.8 gives a thin, blurry-background DoF; a narrow one like f/11 keeps much more in focus.

From the hyperfocal distance H = f²/(N×c) + f, where f is focal length, N the f-number, and c the circle of confusion for your sensor. The near limit is s(H−f)/(H+s−2f) and the far limit s(H−f)/(H−s) for subject distance s. This calculator does the work instantly as you type.

The focus distance that maximises depth of field: focus there and everything from half that distance to infinity is acceptably sharp. Landscape photographers use it to get both foreground and horizon in focus — this calculator shows it for your exact lens and aperture.

The largest blur spot the eye still perceives as a sharp point in a standard-size print. It scales with sensor size: about 0.030 mm on full frame, 0.020 mm on APS-C, and 0.015 mm on Micro Four Thirds. The calculator picks the right value from your sensor selection.

Smaller sensors use shorter focal lengths for the same framing, and shorter lenses have inherently deeper DoF. That is why a phone keeps everything sharp while a full-frame camera blurs backgrounds easily at the same equivalent view.

Open the aperture wide (small f-number), use a longer focal length, get closer to your subject, and put distance between subject and background. The calculator shows how dramatically the DoF thins as you do.

Stop down to around f/8–f/11 and focus at the hyperfocal distance shown by the calculator. Avoid very small apertures like f/22 — diffraction starts softening the whole image.

Rarely. At normal distances roughly one third falls in front of the focus point and two thirds behind; the split approaches 50/50 in macro work and becomes extremely back-heavy near the hyperfocal distance. The calculator shows the exact front/behind split.

Its EXIF metadata records the aperture, focal length and camera. Use the free EXIF viewer on this site — or, on iPhone and iPad, the EXIF Viewer by Fluntro app — to read it from any original photo.

Yes — free, no account, and it runs entirely in your browser with no data sent anywhere. It even works offline once loaded.