Exceljet

Quick, clean, and to the point

Decrease by percentage

Excel formula: Decrease by percentage
Generic formula 
=number*(1-percent)
Summary 

To decrease a number by a specific percentage, you can use a formula that multiplies the number by 1 minus the percentage. In the example shown, the formula in cell E5 is:

=C5*(1-D5)

The results in column E are decimal values with the percentage number format applied.

Explanation 

In this example, the goal is to decrease the prices shown in column C by the percentages shown in column D. For example, given an original price of $70.00, and an decrease of 10% ($7.00), the result should be $63.00. The general formula for this calculation, where "x" is the new price, is:

x=old*(1-percentage)
x=70*(1-10%)
x=70*0.90
x=63.00

Converting this to an Excel formula with cell references, the formula in E5 becomes:

=C5*(1-D5)
=70*(1-0.1)
=70*0.9
=63.00

As the formula is copied down, the formula returns a new price for each item in the table, based on the percentages shown in column D.

Negative percentages

A negative percentage will have the effect of increasing the original price. For example, with -10% in cell D5 (-0.10), the formula evaluates like this:

=C5*(1-D5)
=70*(1--0.1)
=70*1.10
=77.00

This example explains the general formula for increasing a number by a given percentage.

Formatting percentages in Excel

In mathematics, a percentage is a number expressed as a fraction of 100. For example, 95% is read as "Ninety-five percent" and is equivalent to 95/100 or 0.95. Accordingly, the values in column D are decimal values, with the Percentage number format applied.

Author 
Dave Bruns

Excel Formula Training

Formulas are the key to getting things done in Excel. In this accelerated training, you'll learn how to use formulas to manipulate text, work with dates and times, lookup values with VLOOKUP and INDEX & MATCH, count and sum with criteria, dynamically rank values, and create dynamic ranges. You'll also learn how to troubleshoot, trace errors, and fix problems. Instant access. See details here.

Download 100+ Important Excel Functions

Get over 100 Excel Functions you should know in one handy PDF.