Interest Calculator
See how money grows with compound or simple interest, with or without regular deposits, and how much of the final balance is interest.
INPUT
RESULT
- Final balance16,288.95
- Total deposits10,000.00
- Total interest6,288.95
- Effective annual rate5%
Before tax and inflation. Banks may round or credit interest differently.
Balance by year
| Year | Deposits | Interest | Balance |
|---|---|---|---|
| 1 | 10,000.00 | 500.00 | 10,500.00 |
| 2 | 10,000.00 | 1,025.00 | 11,025.00 |
| 3 | 10,000.00 | 1,576.25 | 11,576.25 |
| 4 | 10,000.00 | 2,155.06 | 12,155.06 |
| 5 | 10,000.00 | 2,762.82 | 12,762.82 |
| 6 | 10,000.00 | 3,400.96 | 13,400.96 |
| 7 | 10,000.00 | 4,071.00 | 14,071.00 |
| 8 | 10,000.00 | 4,774.55 | 14,774.55 |
| 9 | 10,000.00 | 5,513.28 | 15,513.28 |
| 10 | 10,000.00 | 6,288.95 | 16,288.95 |
Runs entirely in your browser. Nothing you enter is sent to a server.
How to calculate interest
Enter the starting amount and rate
Type what you start with, the yearly interest rate and how many years the money stays in.
Choose how interest is added
Pick yearly, quarterly, monthly or daily compounding, or simple interest, which is never added to the balance.
Add deposits
Optional: enter a regular deposit, every month or every year, at the start or end of the period. The table shows the balance year by year.
Compound and simple interest
With compound interest, interest is added to the balance and earns interest itself. With simple interest it's paid on the deposits only. 10,000 at 5% for 10 years grows to 16,288.95 compounded yearly, and to 15,000 with simple interest.
How it's calculated
Interest builds up month by month at the yearly rate / 12 and is added to the balance on each compounding date; daily compounding is credited monthly at the matching rate. Deposits earn interest from the month they're made. Tax and inflation aren't taken into account.
Frequently asked questions
What is the effective annual rate?
The yearly rate you actually earn once compounding is included. 5% compounded monthly is worth 5.116% a year.
Does it work for debts?
It shows how a balance grows when nothing is paid back. To see the payments on a loan, use the Loan Calculator.
Is anything sent to a server?
No. The calculation and the CSV file are made in your browser.