Skip to content
ENExplore Calculators

Lens Working Distance Calculator

Work out lens working distance instantly with clear inputs, formula shown and shareable results.

About Lens Working Distance Calculator

Rearranging the field of view relation gives working distance = FOV x focal length / sensor width. Depth of field then follows from magnification and aperture: it shrinks with the square of magnification, which is why close-up inspection needs a small aperture and plenty of light.

Formula

Working distance

WD = FOV x focal length / sensor width; DoF grows with f-number and falls with magnification squared

Worked example

With the default values below, Lens Working Distance Calculator returns Working distance required of 283.29. Change any input above and every figure here is recalculated in your browser.

Inputs used

Focal length
25 mm
Required field of view
80 mm
Sensor width
7.06 mm
Aperture f-number
4 f/

Results

Working distance required
283.29 mm
Magnification
0.08825 x
Approximate depth of field
11.18 mm
Distance including flange
308.29 mm

Step by step

  1. 1Values used
  2. 2Working distance
  3. 3Working distance required= 283.29 mm
  4. 4Magnification= 0.08825 x
  5. 5Approximate depth of field= 11.18 mm
  6. 6Distance including flange= 308.29 mm

Assumptions and limits

  • The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 5 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why does depth of field collapse at high magnification?

It scales as 1/m squared. At 1:1 magnification depth of field is a fraction of a millimetre even at f/8, so part height variation must be tightly controlled.

Should I stop the lens down further?

Only to a point. Beyond about f/8-f/11 on a small-pixel sensor, diffraction blurs detail faster than depth of field improves.

Related Calculators

Lens Working Distance Calculator | Calcrivo