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#Statistical

GROWTH

Excel Functions

Forecast exponential growth by fitting an exponential curve to existing data and predicts values.

Syntax

EXCEL 
=GROWTH(known_y, [known_x], [new_x], const)

Arguments

Parameter Description
known_y The set of y-values you already know in the relationship y = b*m^x.
known_x [optional] The set of x-values that correspond to known_y. If omitted, known_x is assumed to be {1,2,3,...}.
new_x [optional] The new x-values for which you want GROWTH to return corresponding y-values. If omitted, new_x is assumed to be the same as known_x.
const A logical value that controls whether the exponential curve starts at a calculated base value or at 1. If TRUE or omitted, the function calculates the optimal starting value (b) for the curve y = b*m^x. If FALSE, the function forces the curve to start at 1, using the form y = m^x.

Return Value

Returns an array of predicted y-values for the specified new x-values.

Details

The GROWTH function calculates exponential growth predictions based on existing data points. It fits an exponential curve (y = b*m^x) to your known data and then uses that curve to predict future values. GROWTH is particularly useful for forecasting trends that follow exponential patterns, such as population growth, compound interest, or viral spread. The GROWTH function takes up to four arguments in this syntax: In its simplest form, you can use GROWTH with known y-values and x-values, plus new x-values for prediction. Here is an example: The function fits an exponential curve to your data and returns predicted values for the specified new x-values. In the example below, we have data for years 3-7 and want to predict values for years 0-10 (both past and future). The formula in cell F5 is:

Examples

Example #1 - Basic GROWTH calculation

The GROWTH function takes up to four arguments in this syntax:

EXCEL 
=GROWTH(known_y, [known_x], [new_x], [const])
Example #1 - Basic GROWTH calculation

In its simplest form, you can use GROWTH with known y-values and x-values, plus new x-values for prediction. Here is an example:

EXCEL 
=GROWTH({100,150},{1,2},{2,3,4}) // spills {150,225,337.5}
Example #2 - Predict future and past values

In the example below, we have data for years 3-7 and want to predict values for years 0-10 (both past and future). The formula in cell F5 is:

EXCEL 
=GROWTH(C5:C9,B5:B9,E5:E15)
Example #3 - Interpolate fractional values

The formula in cell F5 is:

EXCEL 
=GROWTH(D5:D9,C5:C9,E5:E13)
Example #4 - Using the const parameter

The const parameter controls whether the exponential curve starts at one or some base amount at x=0. For example, when const=TRUE (the default behavio

EXCEL 
=GROWTH(C5:C9,B5:B9,E5:E15,TRUE)
Example #4 - Using the const parameter

In contrast, when const=FALSE, GROWTH sets the constant b to equal 1, fitting the curve y = m^x:

EXCEL 
=GROWTH(C5:C9,B5:B9,E5:E15,FALSE)

See Also

FORECAST LINEST