FORECAST
TheFORECAST
function in Google Sheets is a statistical function that predicts a future value along a linear trend. It returns the predicted value for a chosen x value based on the linear regression of a set of known x and y values. This function is commonly used in finance to predict future values.
 How to use
FORECAST
formula?  Examples of using
FORECAST
formula FORECAST
formula not working? Similar formulas to
FORECAST
Usage
Use the FORECAST
formula with the syntax shown below, it has 3 required parameters:
 x (required):
The x value for which you want to predict the corresponding y value.  data_y (required):
An array or range of the y values in the data set.  data_x (required):
An array or range of the x values in the data set, corresponding to the y values in thedata_y
parameter.
Examples
Here are a few example use cases that explain how to use theFORECAST
formula in Google Sheets.
Predicting future sales
A business can use FORECAST
to predict future sales based on previous sales data. By inputting the known sales values as data_y
and the corresponding time period as data_x
, a business can predict future sales by inputting a future time period as x
.
Budget forecasting
A company can use FORECAST
to predict future costs or revenue based on previous data. By inputting the known cost or revenue values as data_y
and the corresponding time period as data_x
, a business can predict future costs or revenue by inputting a future time period as x
.
Stock price prediction
Investors can use the FORECAST
function to predict the future stock price of a company based on its past performance. By inputting the known stock prices as data_y
and the corresponding time period as data_x
, investors can predict future stock prices by inputting a future time period as x
.
Common Mistakes
FORECAST
not working? Here are some common mistakes people make when using the FORECAST
Google Sheets Formula:
Incorrect data range
One common mistake is to select the wrong data range for the data_y and data_x arguments. Make sure the data ranges are correct and include all the necessary data points.
Nonnumeric input
Another mistake is to include nonnumeric values in the data_y and data_x ranges. Make sure all values are numeric and formatted as numbers.
Insufficient data points
If there are not enough data points in the data_y and data_x ranges, the forecast may be inaccurate or not possible. Make sure there are enough data points for an accurate forecast.
Incorrect x value
Make sure the x value used in the formula is within the range of the data_x values. Using an x value outside of this range will result in an inaccurate forecast.
Missing arguments
Make sure all three arguments (x, data_y, and data_x) are included in the formula. Leaving out any of these arguments will result in an error.
Related Formulas
The following functions are similar to FORECAST
or are often used with it in a formula:

TREND
The
TREND
formula is used to calculate future values based on historical data. It fits a straight line (using the method of least squares) to the arrays specified in theknown_data_y
andknown_data_x
parameters and then uses that line to calculate new yvalues for the array specified in thenew_data_x
parameter. Ifb
is set to TRUE, then the calculation will include the yintercept of the line. This formula is commonly used in forecasting and trend analysis. 
LINEST
The
LINEST
formula is used to calculate the statistics for a line by calculating the line's slope and yintercept. It is commonly used to find the bestfit straight line for a given set of data points. 
SLOPE
The
SLOPE
formula calculates the slope of the linear regression line that best fits the input data. It is commonly used in statistics to analyze trends and predict future values based on past performance. 
INTERCEPT
The
INTERCEPT
function calculates the point where the line of best fit for a set of data intercepts the yaxis. This function is commonly used in regression analysis to find the constant b in the equation y=mx+b where m is the slope of the regression line.
Learn More
You can learn more about the FORECAST
Google Sheets function on Google Support.