Sagitta Calculator

This tool is intended for educational and dispensing support use.

It calculates approximate sagitta from radius, surface power, and refractive index.

Return to the Optics Study Guide

Calculation Setup

Summary Output

Enter the radius, surface power, and refractive index above, then submit the form.

How It Works

This version uses the approximate sagitta formula from the optics study guide.

Sagitta = (r² × D) / (2000 × (n − 1))

It is useful for practical lens-thickness estimation and for understanding how radius, surface power, and index affect curve depth.