Daily Compound Interest Calculator
Calculate compound interest compounded daily.
See final balance, total interest earned, and a year-by-year breakdown for any principal and rate.
Compound interest is often called the “eighth wonder of the world” — it is interest earned on top of previously earned interest. Daily compounding is the most powerful form because interest is added to your balance every single day, giving you interest on your interest every 24 hours.
The Formula
A = P × (1 + r/n)^(n×t)
Where:
- A = Final balance (what you end up with)
- P = Principal (your starting amount)
- r = Annual interest rate as a decimal (e.g. 5% = 0.05)
- n = Number of compounding periods per year (365 for daily)
- t = Time in years
For daily compounding, n = 365, so the formula becomes:
A = P × (1 + r/365)^(365×t)
Why Daily Compounding Matters
The difference between daily and annual compounding grows larger over time. For example, $10,000 invested at 6% annual interest:
| Years | Annual Compounding | Daily Compounding | Difference |
|---|---|---|---|
| 1 | $10,600 | $10,618 | $18 |
| 5 | $13,382 | $13,498 | $116 |
| 10 | $17,908 | $18,220 | $312 |
| 20 | $32,071 | $33,197 | $1,126 |
| 30 | $57,435 | $60,226 | $2,791 |
The Rule of 72
To estimate how long it takes to double your money, divide 72 by your interest rate. At 6%, your money doubles roughly every 72 ÷ 6 = 12 years.
Practical Uses
- High-yield savings accounts (typically 4–5% APY in 2024/25)
- Certificates of deposit (CDs)
- Money market accounts
- Some bonds and fixed-income instruments
Important Note
This calculator computes growth without additional contributions. For savings with regular deposits, use a compound interest with contributions calculator. Results are for informational purposes only and do not constitute financial advice.