Interpolation

This calculator finds a value between known points by linear interpolation or builds a polynomial through all points. Values are exact.

y = y₀ + (y₁ − y₀) · (x − x₀) / (x₁ − x₀)

Example. The polynomial x² passes through (1, 1), (2, 4), (4, 16), so at x = 3 it gives 9, while linear interpolation gives 10.