Depth of Field Calculator
Find how much of a photo is in focus from focal length, aperture, distance and sensor size.
About the Depth of Field Calculator
Depth of field is the range in front of and behind the focus point that looks sharp. It grows with smaller apertures (bigger f-numbers), shorter focal lengths and greater distance. It depends on the circle of confusion: the largest blur that still looks sharp, conventionally 0.03 mm for full frame.
The formula
H = f² ÷ (N c) + f; near = s(H − f) ÷ (H + s − 2f); far = s(H − f) ÷ (H − s)
Worked example
Example: Depth of field = 0.55 m
- Inputs: Focal length: 55 mm; Aperture f/: 3.1; Focus distance: 3 m; Sensor: Full frame (CoC 0.030 mm).
- Formula: H = f² ÷ (N c) + f; near = s(H − f) ÷ (H + s − 2f); far = s(H − f) ÷ (H − s)
- Result: Depth of field = 0.55 m
Questions people ask
Why is phone background blur weaker?
Tiny sensors and short lenses give deep focus; portrait modes add blur in software.
Does sensor size change DOF?
At the same framing and f-number, smaller sensors give more depth of field.