In this post we take a look at how you can complete percentage calculations in Microsoft Excel. Percentage formulas are some of the most commonly used in Excel, so it pays to know how they’re done.
There’s five common types of percentage calculation you’ll likely need to do. Below you can find an explanation of each of them, with the formula written out in both plain English and in example Excel cell references.
Calculation 1 (the percentage of a total)
If you want to calculate what one value is in relation to another as a percentage, then the formula is = [part] / [total].
So in the example below where the percentage score of a test is being calculated (where the score is 86, and there were 120 available points), the formula in cell D3 is =C2/C3
Calculation 2 (the ending number)
If you have a percentage value, and want to calculate what it represents of a total, then the formula is = [x%] * [total]
The example below looks at what volume of liquid is in a container if it’s 64% full, and the total capacity is 1500ml. This means the formula in cell D3 =C2*C3
Calculation 3 (the starting number)
If you have a value which represents a known percentage of a total, then you can use the following formula to work out what the total is = [part] / [%]
In the example below, we are told there is 540ml of liquid, which represents 36% of the total bottle capacity. To calculate what the total bottle capacity is in cell D3, the formula is =C3/C2
Calculation 4 (the percentage increase)
If you have a number that has increased and want to calculate the percentage increase, then the formula is = ([New Number] – [Original Number]) / [Original Number]
In the example below, the price has increased from $17.00 to $22.50. To calculate the percentage increase the formula in cell D3 is therefore =(C3-C2)/C2
Calculation 5 (the percentage decrease)
The formula for a percentage decrease is actually the same as for a percentage increase, you’ll just end up with a negative percentage at the end.
In the example below, the price has decreased from $40.99 to $33.99, so the formula in cell D3 is =(C3-C2)/C2
Important: remember the correct formatting in Excel
If you’re carrying out percentage calculations in Excel, remember you will need to format your data to show a percentage for calculations 1, 4, and 5, and a number for calculations 2 and 3.
You can format your data from the box highlighted green below:
