Aurora Finance
Calculator

Investment return calculator

Combine a starting balance with monthly contributions and see how they grow over time. Compare different rates and horizons in seconds.

Updated July 2026
$
$
%
Future value
$691,150
Total contributed
$190,000
Investment growth
$501,150

How it works

FV = P × (1 + r/12)^(12t) + PMT × [((1 + r/12)^(12t) − 1) / (r/12)]
  • P is your starting balance.
  • PMT is your monthly contribution.
  • r is the annual return as a decimal.
  • t is the number of years.
  • Compounds monthly — a reasonable proxy for most brokerage accounts.

Worked examples

  • $10,000 start + $500/month at 7% for 30 years = ~$690,000.
  • Doubling the monthly contribution nearly doubles the final balance over long horizons.
  • Time matters most — starting 5 years earlier often beats saving 25% more per month.

Frequently asked questions

What return should I use?

Long-term US stocks have averaged about 10% nominal, roughly 7% real (after inflation). Balanced portfolios produce lower expected returns with lower volatility. Being conservative reduces the risk of over-optimism.

Is this a promise?

No — it's a projection based on your inputs. Actual returns vary year to year; the calculator smooths that into an average.

How is this different from compound interest?

Same underlying math. This calculator lets you combine a starting balance with monthly contributions in one view.

Related

Compound interest calculator
Focus on the growth mechanism.
Retirement calculator
Project against a retirement target.
How to start investing
The habits that make projections real.
Educational information only. Not personalised financial advice. Consult a qualified professional for decisions specific to your situation.