basic

Thin Lens Focal Length and Image Magnification Calculator

1/f = 1/do + 1/di; m = −di/do.

Applies the thin lens equation 1/f = 1/d_o + 1/d_i to find image distance and magnification m = −d_i/d_o. Also indicates real/virtual and upright/inverted.

Marcus Laurent By Marcus Laurent
Published Last reviewed 1 min read

Inputs

cm
cm

Results

Enter values and click Calculate to see results.
Was this helpful?

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

1/f = 1/d_o + 1/d_i; m = −d_i/d_o

In depth

Applies the thin lens equation 1/f = 1/d_o + 1/d_i to find image distance and magnification m = −d_i/d_o. Also indicates real/virtual and upright/inverted.