Compound Interest Calculator

See the power of compound interest. Set an initial deposit, monthly contribution, annual return, and time horizon — supports annual, semi-annual, quarterly, monthly, and daily compounding.

Initial deposit

Monthly contribution

Annual interest rate (%)

Years

Compounding frequency

Currency

Final balance—

Total contributions—

Total interest earned—

Multiplier—

Growth chart

Contributions Interest

Year-by-year breakdown

Features

Initial principal + recurring contributions

Annual / semi-annual / quarterly / monthly / daily compounding

Year-by-year breakdown

Visual growth chart

Total contribution vs interest earned

How to Use

1. Enter your initial principal and monthly contribution.

2. Set the expected annual return rate (reference: long-term stock market ~7%).

3. Choose the investment period and compounding frequency.

4. The chart shows how principal and interest accumulate over the years.

5. Click 'Show table' for a year-by-year breakdown.

About this tool

Compound interest means your returns start earning returns of their own, so growth accelerates over time. This calculator models a starting deposit plus a fixed monthly contribution at an annual interest rate, compounded yearly, half-yearly, quarterly, monthly or daily. The chart separates what you put in from the interest earned, and the year-by-year table shows how the balance builds, which makes the effect of time visible: the last years of a long plan usually add more than the first decade. Use it to compare saving earlier versus saving more, or to see how a lower fee changes the result. The maths is exact for the inputs you give; real investments move up and down, so treat the rate as an assumption, not a promise.

Frequently Asked Questions

What formula does the calculator use?

Without contributions, the balance is P × (1 + r/n)^(n×t), where P is the deposit, r the annual rate, n the number of compounding periods per year and t the years. Each monthly contribution is added at the end of the month, and interest is applied month by month at the rate equivalent to the compounding frequency you chose.

How much difference does compounding frequency make?

Less than most people expect. At 6% a year, annual compounding gives a 6.00% effective yield and daily compounding about 6.18%. The rate, the time horizon and the size of contributions matter far more.

What annual rate should I enter?

Use the rate of the actual product for savings accounts or fixed deposits. For long-term stock investments many planners test several scenarios, for example 4%, 6% and 8%, because returns are not guaranteed and vary by market and period.

Does the result include inflation, taxes or fees?

No. It shows the nominal balance. To approximate purchasing power, subtract expected inflation from the rate; to include fees, subtract the annual fee percentage as well, for example entering 5% instead of 6% for a 1% fee.

What is the Multiplier figure?

It is the final balance divided by the total amount you contributed, including the initial deposit. A multiplier of 2.0 means every unit you put in has grown into two.