basic

Thin-Lens Magnification from Object and Image Distance Calculator

m = −dᵢ / dₒ; also 1/f = 1/dₒ + 1/dᵢ.

Compute the lateral magnification of a thin converging or diverging lens: m = −dᵢ/dₒ, where dₒ is the object distance and dᵢ is the image distance. Also computes the focal length via 1/f = 1/dₒ + 1/dᵢ. Positive m → upright image; negative m → inverted. |m| > 1 → magnified.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

cm
cm

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

m = −dᵢ/dₒ; 1/f = 1/dₒ + 1/dᵢ.

In depth

Compute the lateral magnification of a thin converging or diverging lens: m = −dᵢ/dₒ, where dₒ is the object distance and dᵢ is the image distance. Also computes the focal length via 1/f = 1/dₒ + 1/dᵢ. Positive m → upright image; negative m → inverted. |m| > 1 → magnified.