Lens Equation Calculator
Calculate image distance, magnification, and focal length using the thin lens equation.

Positive for converging, negative for diverging

(solving)
Image Characteristics
20 cm
Focal Length
30 cm
Object Distance
60 cm
Image Distance
-2×
Magnification
10 cm
Image Height
Converging LensReal ImageInverted
Lens Power: 5 D (diopters)
Sign Conventions
  • f > 0: converging lens
  • f < 0: diverging lens
  • dᵢ > 0: real image (opposite side)
  • dᵢ < 0: virtual image (same side)
  • m > 0: upright image
  • m < 0: inverted image

Thin Lens Equation

1/f = 1/dₒ + 1/dᵢ
m = -dᵢ/dₒ = hᵢ/hₒ
Power (D) = 1/f (meters)

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