Lens Power Calculator

Find lens power in diopters from focal length.

Lens power (diopters) 2

Formula: P = 1 ÷ focal length (m)

Step-by-step with your numbers:

1. Values used:

2. Focal length = 0.5

4. Lens power = 2diopters

Did we solve your problem today?

Lens power (used for eyeglasses) is the reciprocal of focal length.

The math behind it

P (diopters) = 1 ÷ focal length in meters. Converging lenses are positive; diverging negative.

0.5 m → +2 diopters.

Glasses prescription?

It's given directly in diopters (e.g. −2.00).