Lens & Mirror Equation Calculator illustration

Lens & Mirror Equation Calculator

Uses the thin-lens and mirror equation to find the image distance and magnification, and describes whether the image is real or virtual, upright or inverted.

Positive for a converging lens or concave mirror, negative for diverging or convex.

Notes

  • 1/f = 1/dₒ + 1/dᵢ; magnification m = −dᵢ/dₒ.
  • A positive image distance is a real image you could catch on a screen; a negative one is virtual, like the enlarged image in a magnifying glass.