mCalculator logo
Savings Calculators

Investment Return Calculator

Project the future value of an investment with initial deposit, monthly contributions, and compounding returns.

Uses monthly compounding — the same approach mutual fund and brokerage projections use.

$
$
%
yr
Projected final value
$691,150
After 30 years at 7% annual return with monthly compounding.
Total contributions
$190,000
Interest earned
$501,150
Growth multiple
3.64×
Overview

How the Investment Return Calculator Works

Small contributions compounded over decades produce numbers that surprise most people. This calculator shows the future value of a starting balance plus monthly contributions at any annual return rate, so you can see the effect of starting earlier, saving more, or targeting a slightly higher return.

Formula

The Math Behind the Calculator

FV = PV × (1+r)^n + PMT × ((1+r)^n − 1) / r, where r is the monthly return and n is total months.

Example

A Worked Example

Starting at $10,000 and adding $500/month for 30 years at a 7% annual return grows to about $693,000. Total contributions are $190,000; the other ~$503,000 is compound growth.

How to use

How to Use the Investment Return Calculator

  1. 1Enter your starting balance and monthly contribution.
  2. 2Set the annual return you expect — 7% is a common long-run assumption for a diversified stock portfolio.
  3. 3Set the number of years you'll stay invested.
  4. 4Read final value, total contributions, and interest earned.
Interpretation

What the Results Mean

  • Final value is the projected balance at the end of the period.
  • Interest earned is the compounding portion — anything above what you actually contributed.
  • Extending the timeline by 5–10 years often doubles the final number thanks to compounding.
Avoid

Common Mistakes to Avoid

  • Using an unrealistic return (12–15%) and building plans that never materialize.
  • Ignoring inflation — see the inflation-adjusted return calculator for real purchasing power.
  • Forgetting fees — a 1% expense ratio compounds against you the same way.
Keep going

Related Calculators

Compound Interest Calculator

Project the future value of savings or investments with monthly contributions and compound growth.

Savings Goal Calculator

Calculate the monthly contribution needed to reach a specific dollar goal by a target date — given a starting balance and expected interest rate.

Emergency Fund Calculator

Calculate your right emergency fund target based on monthly expenses, desired months of coverage, and how fast your current savings reach that target.

Roth vs Traditional IRA Calculator

Compare Roth and Traditional IRA after-tax value at retirement based on your tax rate today vs in retirement.

FAQ

Frequently Asked Questions

What return should I assume?+

5–7% real (after inflation) is a defensible long-run assumption for a diversified equity portfolio; 7–10% nominal.

Does this account for taxes?+

No — this shows gross growth. Use tax-advantaged account calculators for after-tax outcomes.

How is this different from compound interest?+

Same math — this variant emphasises portfolio growth with regular contributions rather than a single deposit.

Financial Disclaimer

This calculator is for educational and estimation purposes only. It does not provide financial, mortgage, tax, investment, or legal advice. Actual rates, payments, taxes, fees, insurance costs, eligibility, and loan terms vary by lender, location, credit profile, and market conditions. Always compare official offers and consult a qualified professional before making financial decisions.

Last updated June 2026 · Prepared by the mCalculator Editorial Team