Compound interest calculator

Put in a starting balance, how much you can add and how often, and a rate. See your money grow year by year — contributions and interest shown separately. Then Recurna Flow shows you the part a calculator can't: what you're actually putting away week by week.

Compound interest calculator

Put in a starting balance, how much you can add and how often, and a rate. See how your money grows year by year.

Future value
$125,510
Total contributions $48,000
Total interest earned $67,510
Investment growth showing contributions and total value year by year. 071320 yr $0 $63k $126k
Principal + contributions Total value

No data to chart.

Year-by-year breakdown
Year Starting balance Contributions Interest earned Ending balance

Recurna Flow

That's how the math compounds. The part a calculator can't show is where the money actually goes week by week — how your day-to-day spending lines up with what you're putting away.

Flow is in invite-only beta — apply once (reviewed weekly), and founding members get Pro free for a year.

Estimates only, not financial advice. Shows growth of a fixed annual return compounded at the selected frequency — excludes taxes, fees, and inflation.

How this math works

Early on, most of the growth you see comes from what you're adding yourself, not from interest — the balance is small, so the interest it earns is small too. Interest becomes a bigger share of the total the longer the balance sits and grows, which is why the contributions and interest are shown separately here rather than as one blended figure. Compounding frequency matters less than most people assume: switching between annual and monthly compounding moves the result by a small amount at typical rates, while the rate itself and how long the money grows for matter far more.

What's doing the work early on — contributions or interest?

In the early years, most of the growth comes from what you're adding yourself, not from interest. Interest becomes a bigger share of the growth later, once the balance is large enough for it to compound meaningfully.

Does compounding frequency matter as much as people think?

Less than most people assume. Switching from annual to monthly compounding changes the result by a small amount at typical rates — the rate and the time horizon matter far more than how often interest compounds.