OhMyCalc

Lens Equation Calculator

Calculate image distance and magnification using 1/f = 1/dₒ + 1/dᵢ. Enter focal length and object distance.

How to Use the Lens Equation Calculator

  1. Enter the focal length of the lens in centimeters.
  2. Enter the object distance from the lens in centimeters.
  3. Click Calculate to find image distance, magnification, and image type.

Riferimento Rapido

DaA
f=10 cm, dₒ=30 cmdᵢ=15 cm, M=−0.5×
f=10 cm, dₒ=20 cmdᵢ=20 cm, M=−1×
f=10 cm, dₒ=5 cmdᵢ=−10 cm (virtual)
Converging lensf > 0
Diverging lensf < 0

Casi d'Uso

Formula

1/f = 1/dₒ + 1/dᵢ → dᵢ = 1/(1/f − 1/dₒ); Magnification M = −dᵢ/dₒ.

Domande Frequenti

What do positive and negative image distances mean?
Positive dᵢ means a real image (formed on the opposite side of the lens); negative means a virtual image.
What does magnification tell me?
The absolute value gives the size ratio; negative magnification means the image is inverted.
Is this calculator free?
Yes, all OhMyCalc calculators are completely free.