Skip to content
Networthy

Compound growth explorer

Separate what you add from nominal growth, then translate the ending balance into today's purchasing power.

3 minutesYou'll need: A starting amount, monthly deposit, horizon, and assumed returnNothing you type leaves your browser

Working sketchINPUT → RESULT
Deposits build the base; modeled growth gradually occupies more of the balance.

Starting example. These made-up figures are here to make the calculator readable. Edit any field; this working copy is not saved.

Start here: replace the example figures with yours, read the main result, then change one number at a time to see what matters most.

Hypothetical—not an index forecast

20y

After the time has passed

After 20 years, the modeled balance is $292,465. You supplied $130,000; the difference is modeled growth of $162,465.
The balance is a calculated projection from the assumptions above, not a forecast of any security or index.
Deposited
$130,000
Nominal growth
$162,465
Today's purchasing power
$178,483$113,982 below the nominal figure
Modeled balanceDepositsToday's dollars

Over 20 years, deposits total $130,000, the modeled nominal balance is $292,465, and purchasing power is $178,483 under the entered inflation assumption.

What changes the answer

At 7.0% a year, growth represents 56% of the nominal ending balance. The longer the horizon, the more the answer depends on an assumption you cannot lock in today.

Move the return down before moving it up. A useful plan should survive a less flattering assumption.

These calculators are educational estimates based on the numbers and assumptions you enter. Real results vary, and projections are not guarantees. Nothing here is personalized investment, tax, or legal advice.

See the assumptions behind this estimate

What the calculator assumes

  • The entered return is an effective annual assumption, converted to an equivalent monthly rate.
  • Deposits arrive at the end of each month; an annual increase starts in month 13.
  • Inflation is applied evenly and reports purchasing power in today's dollars.

What it leaves out

  • The hypothetical return is not an S&P 500 forecast or a promise of a smooth path.
  • Taxes, account rules, fees, and sequence-of-returns risk are not included.

Useful next steps

A projection becomes useful when you can reproduce it and see which assumption is carrying the result.

Public resources only. Networthy has no financial relationship with these sources.

An estimate is a starting point. Test the assumption doing the most work, then take the next question in order.

Choose the next question