How to use the abbe number calculator
Find the Abbe number of a glass, a measure of how much it disperses light. Enter refractive index at sodium d line, index at blue f line, index at red c line in the fields above; the abbe number is computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “Abbe number glass”, “dispersion of lens glass”, “crown or flint glass”, “calculate abbe number”, “find abbe number”.
Formula
Variables
- nd — Refractive index at sodium d line
- nF — Index at blue F line
- nC — Index at red C line
Worked example
With refractive index at sodium d line = 1.5168, index at blue f line = 1.5224, index at red c line = 1.5143, the calculator gives abbe number ≈ 63.80247.
Frequently asked questions
What is the abbe number calculator used for?
Find the Abbe number of a glass, a measure of how much it disperses light. It helps with questions such as “Abbe number glass”, “dispersion of lens glass”, “crown or flint glass”.
What is the formula for the abbe number calculation?
Abbe number = (nd-1) / (nF-nC). Here nd is refractive index at sodium d line, nF is index at blue f line, nC is index at red c line.
What inputs do I need for the abbe number calculator?
You need refractive index at sodium d line, index at blue f line, index at red c line. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the abbe number calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the abbe number result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.