Spreadsheet Practice

Lesson 4 of 29, Foundations

Percentages & growth

Percentages are just decimals with a format applied.

Free7 minutes, 2 exercises%^

Watch it done

2 steps

Watch the technique worked out on sample data, then try it yourself in the exercises.

How it works

Excel stores 25% as 0.25. Calculate with decimals and let the cell format show the percent sign. Don't multiply by 100.

Percent change is (new − old) / old. Growth compounds: a balance growing at rate r for n years ends at start × (1 + r)^n.

Syntax

=(C2-B2)/B2Percent change
=C2/B2-1Same result, shorter
=B2*(1+C2)Add a % increase
=B2*(1+C2)^D2Compound growth

Watch out for

  • Multiplying by 100 and formatting as % shows 2,500% instead of 25%.
  • A negative percent change means a decline. Check it against the raw numbers.

The exercises

  1. Year-over-year change. In D2, calculate the percent change from last year to this year. Fill down to D6.
  2. Compound growth. In E2, calculate the ending balance: start × (1 + rate) raised to the number of years. Fill down to E5.

Year-over-year change

In D2, calculate the percent change from last year to this year. Fill down to D6.