Lens Thickness Calculator

Estimate center and edge thickness of eyeglass lenses based on prescription power, lens index, and frame size.

Sphere Power

Lens Index

Frame Lens Diameter

Pupillary Distance (PD)

Tab to move between fields

Center Thickness

1.5 mm

Edge Thickness

4.42 mm

Estimated Weight (per lens)8.9 g

How to Use This Calculator

Enter your Sphere Power in diopters (negative for myopia, positive for hyperopia).
Select the Lens Index of your chosen material — 1.50 = standard CR-39, 1.67 = high-index, 1.74 = ultra high-index.
Enter the Frame Lens Diameter (the 'A' measurement from the frame in mm) and your Pupillary Distance (PD) in mm.
Review the estimated Center Thickness, Edge Thickness, and Estimated Weight per lens.
Compare different lens index values to find the thinnest and lightest option for your prescription.

What each input means

Sphere Power: Lens prescription sphere power in diopters. Negative for myopia, positive for hyperopia.
Lens Index: Refractive index of the lens material (1.50 = standard, 1.67 = high-index, 1.74 = ultra high-index).
Frame Lens Diameter: Horizontal diameter of the frame lens opening in mm (frame 'A' measurement).
Pupillary Distance (PD): Distance between your pupils in mm. Used to calculate decentration.

Identify Input Parameters
4 parameters
Sphere Power = -4, Lens Index = 1.5, Frame Lens Diameter = 54, Pupillary Distance (PD) = 64 = 4 input(s) provided
Calculate Center Thickness
Center Thickness
1.5 = 1.5
Calculate Edge Thickness
Edge Thickness
4.42 = 4.42
Calculate Estimated Weight
Estimated Weight
8.9 = 8.9