Compound Interest Calculator

Project growth with periodic compounding and end-of-period contributions.

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Behind the answer

FV = P(1+r)^n + C((1+r)^n − 1)/r

How to use this calculator

Choose compounding separately from regular deposits and compare beginning- or end-period contributions. Additional monthly and annual deposits are independent streams. Interest tax is modeled as withholding at each credit; the inflation-adjusted balance expresses purchasing power.

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Formula and method

FV = P(1+r)^n + C((1+r)^n − 1)/r

Constant nominal rate greater than −100% and complete contribution periods. Interest-tax withholding applies only to positive interest; losses do not create an assumed tax credit. It is not a jurisdiction-specific tax calculation. No market volatility or withdrawal sequence is modeled.

Worked example

1,000 at 5% compounded annually for 10 years, without contributions, grows to 1,628.89.

Questions about compound interest calculator

When are regular contributions added?

Choose beginning- or end-period contributions and set deposit frequency independently from compounding. Optional monthly and annual deposits are separate streams. Without contributions, 1,000 at 5% compounded annually for 10 years grows to about 1,628.89 before taxes or fees.

What assumptions should I check?

Are my inputs saved?

Calculations run in your browser. We store only tool IDs for favorites and recent tools. Sharing inputs in links is disabled for this category.

Financial tools model the assumptions shown above and do not predict actual returns or replace lender disclosures or professional advice. Amounts are currency-neutral: use the same currency for every amount. No exchange rate is applied.