Investment Growth Calculator
Put in a starting amount and a monthly contribution, pick a return and a horizon, and watch compounding do the heavy lifting — the split between what you put in and what it earns, the year growth overtakes your contributions, the real value after inflation, and what fees quietly cost you.
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How compound growth turns contributions into wealth
Every period, your balance earns a return, and that return is added back so it earns its own return next period. That's compounding. In the early years most of your balance is simply the money you've contributed — but the growth keeps stacking on itself, and the gap between the two widens.
This calculator pulls out the moments that matter:
- The compounding crossover: the first year your investments grow by more than you contribute — the moment your money does more of the work than you do.
- Nominal vs. real: the raw ending dollars next to what they'd actually buy in today's money, after inflation.
- Fee drag: the lifetime cost of even a 1% annual fee — small per year, but it compounds against you the same way your returns compound for you.
The biggest levers, by far, are time in the market and a return that isn't eaten by fees. A real portfolio never grows in a straight line — treat this as a smooth baseline, not a forecast.
Common questions
- What return should I assume?
- That's your call — this tool doesn't recommend one. For context, a broad stock market has historically averaged roughly 10% nominal (around 7% after inflation) over the long run, but any single decade can be far higher or lower. Lower the number for a bond-heavy mix, and remember the return here is assumed smooth, while real markets swing.
- Does compounding frequency really change much?
- Less than people expect. Going from annual to monthly to daily compounding nudges the result up a little, but the difference is small next to the return rate, the contribution, and the time horizon. The toggle is there so you can match how your account actually compounds.
- Is anything saved or sent anywhere?
- No. Every number runs in your browser. Nothing you type is uploaded, stored, or shared — and you can export the full year-by-year schedule to CSV with one click.
Finding the money to invest is the hard part
Taly auto-splits every paycheck across your budget — so the room to invest a little each month shows up on its own, instead of you hunting for it. Your paycheck does the math.