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How to calculate simple interest in Excel and Google Sheets
Topic:Finance basicsExcel & Google Sheets
=A2*B2*C2✓
Verified example
Computed by a real spreadsheet engine on the sample data below.
| Principal | Rate | Years | Interest |
| 1000 | 0.05 | 3 | |
| 5000 | 0.08 | 2 | |
| 2500 | 0.06 | 1 | |
| 10000 | 0.04 | 5 |
=A2*B2*C2→150
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Step by step
- 1Set up your spreadsheet with three columns: Principal (A), Annual Rate as a decimal (B), and Time in years (C).
- 2In the Interest column, enter =A2*B2*C2. This implements the Simple Interest formula: I = P × r × t.
- 3Format the result as Currency. To also calculate the total repayment, add a column with =A2+(A2*B2*C2) for Principal + Interest.
Tips
- Enter the rate as a decimal (e.g., 0.05 for 5%) rather than a percentage to avoid needing to divide by 100 in the formula.
Need it for your exact data?
Describe your columns in plain English and get the precise formula for your sheet, with the right Excel or Sheets syntax.
Frequently asked
How is simple interest different from compound interest?
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus accumulated interest each period.
What if my time period is in months?
Divide the months by 12 in your formula: =A2*B2*(C2/12), where C2 holds the number of months.
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