Lighting Calculator

Calculate flash guide numbers, lighting ratios, and inverse square law for photography lighting.

Lighting Calculator

Distance = GN / Aperture

Flash Guide Number (at ISO 100)

Aperture (f/)

ISO

Flash-to-Subject Distance

7.14 m

f/5.6 at ISO 100

Guide Number Details

GN at ISO 10040

Effective GN at ISO 10040.0

Distance by Aperture

f/1.428.6m

f/220.0m

f/2.814.3m

f/410.0m

f/5.67.1m

f/85.0m

f/113.6m

f/162.5m