Author: Oscar Cronquist Article last updated on October 16, 2018

The FORECAST function calculates a value based on existing x and y values using linear regression. Use this function to predict linear trends.

This function is outdated and was replaced with FORECAST.LINEAR function in Excel 2016.

Formula in cell E3:


Excel Function Syntax

FORECAST(x, known_y'sknown_x's)


x Required. The data point for which you want to predict a value.
known_y's Required. Known y points.
known_x's Required. Known x points.


The chart below shows the predicted value as a red dot, based on x and y values represented by the blue dots.