See how your savings grow with daily compounding. Enter a starting balance, an annual interest rate, how long you plan to save and an optional daily deposit. The calculator shows your future balance, total interest earned and how much comes from your own contributions.
This is ideal for tracking high-yield savings accounts, money market funds and apps that credit interest every day.
Enter your starting balance, daily deposit and interest rate to see how much your savings can grow with interest applied every day.
Many bank accounts and savings apps credit interest every day. This calculator estimates what your balance could be after a chosen time period, assuming:
The math splits into two parts: growth of the starting balance, and growth of the daily deposit stream.
If you invest a lump sum P at a nominal annual rate r,
compounded daily, the daily rate is:
Daily rate = r / 365
After N days, the future value (FV) is:
FV = P × (1 + r/365)^N
where:
P = starting balancer = nominal annual interest rate (as a decimal)N = number of days invested
If you also add a fixed amount D at the end of every day, the
future value becomes the sum of the grown starting balance and a daily annuity:
FV = P × (1 + r/365)^N + D × [((1 + r/365)^N − 1) / (r/365)]
The calculator uses this formula behind the scenes (and a simpler version if the interest rate is zero). It also tracks how much of the final balance comes from:
Suppose you start with $10,000, earn 4.5% interest compounded daily, and add $5 per day for 5 years:
Plugging these into the calculator gives a future balance (for illustration) of roughly:
You can then see exactly how much of your growth came from interest versus the habit of adding a small daily amount.
Banks often quote a nominal annual rate but pay interest daily. The true rate you experience over a year is higher due to compounding. The relationship is:
Effective annual rate (EAR) = (1 + r/365)^365 − 1
This calculator shows both the nominal rate you enter and the implied effective annual yield so you can compare accounts that compound annually, monthly or daily.
It uses 365 days per year for daily compounding. Some financial institutions use other conventions, but 365 is standard for personal savings comparisons.
In real life, a negative daily deposit would mean daily withdrawals. This version assumes a non-negative daily deposit; if you enter a negative value, it is treated as zero to keep the focus on saving rather than drawing down.
No. For simplicity, the calculator counts every calendar day the same. Many banks also use this approach and accrue interest on balances even on non-business days.
No. The values are in nominal terms. To understand your real return, you would need to factor in taxes on interest and the effect of inflation separately.