Lensmaker's Equation Calculator

The Lensmaker equation is used to determine whether a lens will behave as a converging or diverging lens. The calculations are based on the curvature of its faces and the relative indices of the lens material and the surrounding medium. It is also used to calculate focal length of lens. The focal length f is positive for converging lenses, and negative for diverging lenses. Make use of this online Lensmaker's equation calculator to determine whether the lens is converging or diverging one.

gmol/liter
kelvin

Result :

Example:

Calculate the focal length of lens given that,
Radius of Curvature of the First Surface: 40
Radius of Curvature of the Second Surface: 50
Refractive Index of Lens Material: 60gmol/liter
Refractive Index of Ambient Medium: 10 kelvin

Solution:

1/f = (n1/nm-1) x (1/r1-1/r2)
1/f = (60/10-1) x (1/40 - 1/50)
1/f = (60/9) x (0.025 - 0.02)
1/f = (6.66)x(0.005)
1/f = 0.0333
Focal Length: 0.0333