Lensmaker's Equation calculator
Focal length of a thin lens from radii and refractive index.
Category: Geometric Optics
Formula: 1/f = (n-1)·(1/R₁ - 1/R₂)
Inputs
| Input | Parameter | Unit | Default |
|---|---|---|---|
| Index n | n | 1.5 | |
| R₁ | R1 | mm | 100 |
| R₂ | R2 | mm | -100 |
Result with the default inputs
- Focal length: 100 mm
- Power: 10 D
Open it with your own values: put each input in the address as a parameter, for example /calculators/lensmakers-equation?n=1.5. A unit other than the listed one goes in <parameter>_unit.
Read more: Wikipedia: Lens, Lensmaker's equation