Mirror Equation Calculator — Formula
## Mirror Equation
The mirror equation is identical in form to the thin lens equation.
### Formula
**1/f = 1/d_o + 1/d_i**
For a concave mirror, f is positive. For a convex mirror, f is negative. The focal length equals half the radius of curvature: f = R/2.
The mirror equation is identical in form to the thin lens equation.
### Formula
**1/f = 1/d_o + 1/d_i**
For a concave mirror, f is positive. For a convex mirror, f is negative. The focal length equals half the radius of curvature: f = R/2.
Esempio Risolto
An object 40 cm from a concave mirror with f = 20 cm.
- 1/f = 1/do + 1/di
- 1/20 = 1/40 + 1/di
- 1/di = 1/20 - 1/40 = 1/40
- di = 40 cm
- M = -40/40 = -1 (inverted, same size)