Investment Calculators
Project growth, measure returns and test what history says about the market. 9 free calculators, each with its formula and a worked example.
Other categories
Grow your money
Compound Interest CalculatorSee how a deposit grows with compounding, extra contributions and different compounding frequencies.Investment CalculatorProject what a starting balance and monthly investing could grow to, before and after inflation.S&P 500 CalculatorSee what money invested in the S&P 500 grew to in any period since 1928, with dividends and inflation.401(k) Investment CalculatorProject a 401(k) with your contributions, the employer match, raises and the 2026 IRS limits.Roth IRA CalculatorProject your Roth IRA’s tax-free balance and check how much you can contribute for 2026 at your income.
Measure returns
ROI CalculatorMeasure return on investment and the annualized return, and compare two investments side by side.Stock Profit CalculatorWork out profit or loss on a trade after commissions, with return, annualized return and break-even price.Stock Average CalculatorFind your average cost per share across several buys and see how a new purchase changes it.Dividend CalculatorEstimate dividend income, yield and the effect of reinvesting dividends over the years.
Which calculator answers your question?
- How much will my money grow?
- Compound Interest Calculator: growth of a deposit and regular additions at any compounding frequency, with time to double.
- What will investing every month add up to?
- Investment Calculator: the future value of monthly contributions, in today’s dollars too, or the return you need to reach a goal.
- What return did I actually earn?
- ROI Calculator: total and annualized return, so investments held for different lengths of time compare fairly.
- Am I up or down on a stock?
- Stock Profit Calculator: profit or loss after fees, dividends and an estimated tax; for several purchases, the stock average calculator gives your average cost.
- How much income will dividends pay?
- Dividend Calculator: yearly and monthly dividend income, with or without reinvesting, and how it can grow.
- What did the S&P 500 return over a period?
- S&P 500 Calculator: the historical result of any start and end year from 1928 to 2025, with dividends reinvested and after inflation.
- Will my 401(k) be enough?
- 401(k) Investment Calculator: your balance at retirement with your employer’s match and the 2026 contribution limits.
- How much can I put in a Roth IRA, and what will it grow to?
- Roth IRA Calculator: your 2026 contribution limit after the income test and the tax-free balance it can build.
How these calculators work
Every calculator here shows the formula it uses, a worked example and the assumptions behind the result. Figures that change each year, such as tax brackets and contribution limits, carry the year they apply to and the official source. Everything runs in your browser: you don't sign up, and nothing you type is sent anywhere.
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