How is the future value of monthly investments calculated?

Future value = P × ((1 + i)^n − 1) / i × (1 + i), where P is the monthly contribution, i is the monthly rate of return, and n is the number of months. Contributions are assumed to be made at the start of each month.

Is investing monthly better than a lump sum?

It depends on the market. Monthly investing reduces timing risk by spreading purchases over time and builds discipline. A lump sum can outperform in steadily rising markets, but carries higher timing risk.

What rate of return should I assume?

A globally diversified equity portfolio has historically returned around 7–10% annually over long periods. Use a conservative estimate like 6–8% for planning, and adjust based on your risk tolerance.

Does this calculator account for inflation or taxes?

No. The result is a nominal future value. For real (inflation-adjusted) returns, subtract expected inflation from the annual rate. Taxes depend on your jurisdiction and are not modelled here.

How much should I invest per month?

A common guideline is 15–20% of gross income for long-term goals like retirement. Start with whatever you can sustain, increase by 1% of income with each raise. The habit of consistent investing matters more than the initial amount.

What happens if I skip contributions for a month?

Missing one month has little effect, but regular gaps compound the loss. Skipping 10,000/month for a year removes that year's contributions plus all future returns they would have generated — over 30 years, that is over 100,000 in foregone value at 8% annually.

Monthly Investment Calculator

Project the future value of regular monthly contributions. Enter the amount, expected return and years to see the total invested, the gains earned and what share of the final amount came from returns.

How to use

Enter monthly contribution

Type the amount you invest each month.

Set the expected return

Enter the annual rate of return as a percentage.

Choose the period

Enter the number of years you plan to invest.

Read the projection

See the future value, total invested, and investment gains.

Features

Future value projection

See what your regular monthly contributions will grow to over time.

Total invested vs gains

Separates the money you put in from the money earned through returns.

Gain share percentage

See what portion of the final amount came from investment gains.

Works for any currency

Enter amounts in any currency — the math is identical.

Common use cases

Project the growth of a monthly savings plan
Compare investing 100 vs 500 per month over 20 years
See how compound returns accelerate over long periods
Plan contributions for a retirement account

Frequently Asked Questions

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