Course outline / Basic formulas
Lesson 5 of 75 · Beginner · 5 exercises
Working with percentages
Percent of a total, percentage change, and increasing or decreasing by a percentage.
What you'll practise
- Find a percentage of a number
- Percentage change
- Share of a total
- Increase by a percentage
- Decrease by a percentage
Find a percentage of a number
In Excel, 15% is stored as the number 0.15. To find 15% of something, just multiply by it.
=200*15% gives 30.
In cell E2, work out the rate in F2 of this year's sales in C2.
Percentage change
Percentage change compares a new value with an old one:
=(new - old) / old
A positive result is growth; a negative result is a fall.
In cell E2, work out the percentage change in sales from last year (B2) to this year (C2).
Share of a total
To see what part one number is of another, divide the part by the whole. The result is a fraction that shows as a percentage when the cell has the % format.
In cell E2, work out this year's costs (C3) as a share of this year's sales (C2).
Increase by a percentage
To raise a value by a percentage, multiply it by 1 plus the rate. A 15% rise is the same as multiplying by 1.15.
In cell E2, increase last year's sales in B2 by the rate in F2.
Decrease by a percentage
A discount works the other way: multiply by 1 minus the rate. Taking 15% off means paying 85%.
In cell E2, reduce this year's sales in C2 by the rate in F2.
Try it in a real spreadsheet
Every step checks your answer instantly and tells you exactly what to fix.