🔍 Lens Maker Equation Calculator
Calculate the focal length of a thin lens using the lens maker’s equation, based on its refractive index and surface curvatures.
What the lens maker equation finds
The lens maker’s equation relates a thin lens’s focal length to its material’s refractive index and the curvature of its two surfaces, letting opticians and students predict how a lens will focus light before it’s even made.
The formula used
This calculator uses 1/f = (n − 1)(1/R1 − 1/R2), where n is the refractive index of the lens material, and R1 and R2 are the radii of curvature of the first and second lens surfaces respectively, using the standard sign convention (positive if the center of curvature is on the outgoing side of the surface).
This equation assumes a thin lens (negligible thickness) surrounded by air or vacuum on both sides. For general physics education purposes.