Compound Interest Calculator

See how a starting amount plus regular deposits grows over the years when interest earns interest. Free, no sign-up, and it runs in your browser: nothing you type is sent anywhere.

Free, no sign-up
Runs in your browser
Updated October 29, 2026

Balance after 10 years: 17,175.24
Total you put in: 13,000.00
Interest earned: 4,175.24

Year	Put in	Interest	Balance
1	2,200.00	79.05	2,279.05
2	3,400.00	223.53	3,623.53
3	4,600.00	436.81	5,036.81
4	5,800.00	722.38	6,522.38
5	7,000.00	1,083.97	8,083.97
6	8,200.00	1,525.44	9,725.44
7	9,400.00	2,050.90	11,450.90
8	10,600.00	2,664.64	13,264.64
9	11,800.00	3,371.17	15,171.17
10	13,000.00	4,175.24	17,175.24

Monthly additions are made at the end of each month. Real returns vary; this assumes a fixed rate.

Read the full guide: Compound Interest Explained With Simple Examples

How to use the compound interest calculator

Quick answer: To use the compound interest calculator, enter what you start with, add a monthly deposit, set the rate and years and read the year-by-year table.

Enter what you start with. Your current savings or investment.
Add a monthly deposit. Even small regular amounts make a big difference over time.
Set the rate and years. Use a realistic yearly return.
Read the year-by-year table. See how much came from you and how much from interest.

Why starting early matters

Interest earns interest, so growth speeds up over time. Money invested 10 years earlier often ends up worth more than larger amounts invested later.

Frequently asked questions

What is the compound interest formula?

A = P(1 + r/n)^(nt) for a single amount, where n is how often interest is added per year. Regular deposits are added on top.

Does it include inflation or tax?

No. Lower the rate to allow for them. Results are estimates for planning, not professional advice.