Interpolation Calculator

Use this free interpolation calculator to estimate a value between two known points by linear interpolation.

How the interpolation calculator works

y = y₁ + (x − x₁) × (y₂ − y₁) ÷ (x₂ − x₁). It assumes a straight line between the two known points.

Frequently asked questions

When should I use interpolation?

Use it to estimate a value that lies between two measured points, such as a table lookup.

Results are estimates for general information only. They are not a substitute for professional advice where applicable. Found a mistake? Report an error.