Spherical Mirror Equation

Find the image distance, magnification and image type for a concave or convex mirror, free online.

Focal length f (cm; + concave, − convex)

Object distance (cm)

About this calculator

The mirror equation is 1/f = 1/d₀ + 1/dᵢ and the magnification is m = −dᵢ/d₀. Use a positive focal length for a concave (converging) mirror and a negative one for a convex mirror. A negative image distance means a virtual image behind the mirror.