Input details
Detailed schedule
| Period | Year | Balance | Total contributions | Total interest |
|---|---|---|---|---|
| Run a calculation to see your period-by-period schedule here. | ||||
Example compound APY comparisons
Illustrative examples showing how compounding frequency affects effective annual percentage yield and final balance for the same nominal rate.
| Nominal rate | Compounding frequency | Computed APY | Initial deposit | Term (years) | Final balance |
|---|---|---|---|---|---|
| 5% | Annual | 5.000% | $10,000 | 10 | $16,288.95 |
| 5% | Monthly | 5.116% | $10,000 | 10 | $16,470.09 |
| 5% | Daily | 5.127% | $10,000 | 10 | $16,486.78 |
Formula used
The effective annual percentage yield (APY) from a nominal rate r compounded n times per year is:
APY = (1 + r / n)n − 1
Future value with regular contributions per period C, initial deposit P, periodic rate i = r / n,
and total periods m = n × years is:
Final balance = P × (1 + i)m + C × ((1 + i)m − 1) / i
When the periodic rate is zero, the balance equals the initial deposit plus contributions with no interest growth.
Nominal rate versus effective APY
The nominal rate is the stated yearly percentage without compounding. APY converts that nominal rate into a true yearly growth measure. Higher compounding frequencies push APY above the nominal rate.
For example, a six percent nominal rate compounded monthly yields. APY of about six point one seven percent instead. Small percentage improvements become meaningful on longer timelines.
Impact of compounding frequency
Compounding frequency decides how often interest is added to balance. Each compounding event lets future interest earn interest again. Moving from annual to monthly increases the effective growth rate.
The calculator lets you switch between annual, monthly, weekly, daily. Instantly see resulting APY and final balance values. This helps you choose between alternative savings account offers clearly.
Role of regular contributions
Regular contributions often dominate final balance on long horizons. Small monthly deposits compound alongside the original starting deposit. Contributions at period beginning earn more interest than contributions later.
The tool models either beginning or end timing exactly. Period timing changes total interest and years needed goals. Experiment by increasing contributions until results match your objectives.
Accounting for inflation in real terms
Nominal balances ignore increasing prices over long investment periods. Real return considers how much purchasing power really grows. Inflation adjustment divides final balance by cumulative inflation factor.
The calculator estimates inflation adjusted balance using chosen rate. This reveals whether savings merely track prices or beat them. Use different inflation assumptions to test conservative planning scenarios.
Comparing compound APY with simple interest
Simple interest applies the rate only to original contributed principal. Compound interest applies the rate to both principal and interest. Over time compound growth can dramatically exceed simple interest growth.
The summary includes an approximate simple interest comparison figure. You can see extra balance generated purely from compounding. Larger gaps appear with higher rates or longer saving periods.
How to use this calculator
- Choose your currency, then enter initial deposit and nominal annual rate.
- Set investment term, compounding frequency, and regular contribution amount if needed.
- Optionally include annual fees, expected inflation, and a target balance goal.
- Select “Calculate compound APY” to update the APY, summary, schedule, and growth graph.
- Download the detailed schedule as CSV, or save a summary PDF for your records.