# Lagrange Interpolation Calculator

Lagrange interpolation calculator is a free online tool used to find the equation of a function when the coordinate points are given. BYJU’S Lagrange interpolation calculator tool is simple and easy to access. Enter the coordinate points on the input field, and it displays the Lagrange interpolation polynomial in the output field.

Lagrange interpolating polynomial is a method of calculating the polynomial equations for the corresponding curves that have coordinates points. This method provides a good approximation of the polynomial functions. Lagrange polynomial is a polynomial with the lowest degree that assumes each value to the corresponding values. When applying Lagrange interpolation for the given set of points with unequal values, the function coincides with each point. Use the online Lagrange calculator tool to find the polynomial for the given set of distinct coordinates points x and y corresponding to the value of x.

## Finding Lagrange Polynomial

To find the Lagrange interpolating polynomial, the following formula is used.

$P(x) = \sum_{j=0}^{n}y_{j}\left ( \prod_{i=0,i\neq j }^{n}\frac{X – x_{i}}{x_{j}-x_{i}} \right )$

With the coordinates (x0, y0), …., (xn, yn) and distinct xi.