See what daily compounding
does over time
Interest is worked out on the real calendar, one day at a time, and capitalised into the balance so the next day earns on a slightly bigger figure. The projection updates as you type.
Balance over time
Breakdown
The formula
With a fixed daily rate, the balance after t days is:
A = P (1 + r)t
If you enter an annual rate instead, it is divided across the year first, so the daily rate is r / 365 and the balance after t years is:
A = P (1 + r/365)365t
Where A is the investment value, P the principal and r the rate as a decimal. Percentage profit is the interest earned divided by the principal.
Worked example
A principal of $50 at 1% per day for one year compounds every one of the 365 days:
50 × 1.01365 = 1,889.17
- Investment value $1,889.17
- Total interest / earnings $1,839.17
- Percentage profit 3678.3%
Set the reinvest rate below 100% and only that share of each day's interest is capitalised — the rest is paid out and stops compounding.
This calculator is a projection tool. It assumes the rate you enter stays fixed for the whole term and ignores fees, taxes and inflation. Real returns vary, and nothing here is a forecast or a guarantee — it is not investment advice.