Magnification Calculator

M = -d_i/d_o = h_i/h_o. Linear magnification of a lens or mirror.

Inputs

Result

Magnification
0.5000
reduced, upright.
  • Sourcedistances
  • M0.500000
  • |M|0.5000
  • Orientationupright
  • Sizereduced

Step-by-step

  1. M = -d_i / d_o = -(-15) / 30 = 0.5000.

How to use this calculator

  • Pick distance or heights.
  • Enter values.
  • Read M with sign.

About this calculator

Linear magnification = ratio of image size to object size, with sign indicating orientation. M = h_i / h_o = -d_i / d_o. |M| > 1 enlarged; < 1 reduced. Sign +: upright (virtual image); −: inverted (real image). Microscope: M = 100-1000+. Camera capturing distant object: M ≈ f / d_o (very small fraction). Magnifying glass: M = 1 + d_n/f where d_n is near-point distance ~25cm.

Frequently asked

Real images form on opposite side of object — inverted. Sign convention encodes this.

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