Compound interest calculator

See how much your money can grow with interest on interest, adding a starting amount and a deposit every month. Works with any currency.

您的結果會顯示在這裡 填寫欄位並點選 Calculate growth.

How we calculate

Each month’s interest is added to the balance and starts earning interest too. The monthly deposit goes in at the end of each month.

Final amount = Starting × (1 + i)ⁿ + Deposit × ((1 + i)ⁿ − 1) ÷ i

商 = monthly rate as a decimal · n = months. A yearly rate becomes the equivalent monthly rate: i = (1 + yearly rate)^1/12 − 1. Taxes and fees are not deducted.

常見問題

Is this return guaranteed?

No. It is a projection with a fixed rate. In real life the rate can change, and taxes and fees lower the result.

Which rate should I use?

Use the rate of the investment you are looking at, per month or per year.

Can I leave the monthly deposit out?

Yes. Set the deposit to 0 to see only how the starting amount grows.

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