Example 1
- Principal: 10,000
- Rate: 6%
- Years: 10
Final amount ≈ 17,908.48
Interest ≈ 7,908.48
Compound interest calculator: 10,000 at 6% for 10 years (yearly) → ≈ 17,908.48.
Compound interest calculator
The compound interest calculator applies the formula: principal × (1 + (rate/100)/n) to the power of (n × years). By default, n is 1, so 10000 at 6% for 10 years is about 17908.48. You can choose semiannual, quarterly, monthly, or daily compounding and add an optional contribution. There is no deposit tax field.
Result
Enter principal, rate, years, and compounding. An optional contribution is in the section under the compounding menu. The result appears here.
The final amount = principal × (1 + (rate/100)/n)^(n × years). 10000, 6%, and 10 years with n = 1 is about 17908.48. Months and an optional tax estimate are on term deposit. Article: compound interest.
How results are calculated
Principal10000
Rate6%
Years10
CompoundingYearly
Contribution0
Final amount17908.48
The compound interest calculator uses principal, the annual rate, years, and compounding. With no contribution, the final amount = principal × (1 + (rate/100)/n)^(n × years), where n is 1, 2, 4, 12, or 365. Interest equals the final amount minus principal minus contributions. There are no fees or tax withheld on this page.
At 10000, 6%, 10 years, and yearly compounding, the result is about 17908.48. The same three numbers with monthly compounding give about 18193.97. With a contribution of 100 at the end of each month the final amount is about 34581.90, with 12000 of your own contributions.
Enter principal, rate, and years. In the Compounding menu, leave yearly or pick another frequency. Under Contribution (optional) you can add a monthly or yearly amount. A blank contribution is 0. Click Calculate and read the final amount, interest, the effective annual rate, and the year-by-year table.
The term deposit page uses months, a CD menu, optional APY, and an optional tax estimate. Future value adds beginning-of-period timing, inflation, and a target. On this page a contribution is always at the end of the period.
A flat rate for a decade is a classroom assumption. A promo that drops after a year, and tax on interest, will move a real balance. Daily compounding uses 365 periods, not a bank calendar.
Enter 10000, 6, and 10, and leave yearly compounding. The result is about 17908.48. Then set monthly compounding and compare a result of about 18193.97.
How to use the calculator
- In the Principal field, enter the starting amount, for example 10000. Zero is allowed when you enter a contribution.
- In the Annual rate field (% p.a.), enter the percent, for example 6. In the Years field, enter the horizon, for example 10.
- In the Compounding menu, leave yearly or choose semiannual, quarterly, monthly, or daily.
- Optionally open the Contribution section and enter an amount. Frequency is monthly or yearly. The contribution is added at the end of the step, after interest.
- Click Calculate. At 10000, 6, 10, and yearly compounding, the final amount is about 17908.48. With monthly compounding the final amount is about 18193.97. With a contribution of 100 each month the final amount is about 34581.90.
Compound interest with a compounding menu
With no contribution the formula is: principal × (1 + (rate/100)/n)^(n × years). 10000 at 6% for 10 years is about 17908.48 when n is 1, and about 18193.97 when n is 12.
- n
- Compounding periods per year: 1, 2, 4, 12, or 365. The default is 1.
- contribution
- This is an amount at the end of each month or year, after that step’s interest. 100 a month for 10 years is 12000 of your own contributions.
- effective
- The effective annual rate from the compounding frequency n, ignoring deposits: (1 + (rate/100)/n)^n − 1. At 6% and n = 12 it is about 6.17%.
Usage examples
Example 2
- Principal: 25,000
- Rate: 5%
- Years: 5
Final amount ≈ 31,907.04
What does 25,000 become at 5% for 5 years? 25,000 × 1.05^5.
Example 3
- Principal: 5,000
- Rate: 8%
- Years: 15
Final amount ≈ 15,860.85
What does 5,000 become at 8% for 15 years? 5,000 × 1.08^15.
Example 4
- Principal: 10,000
- Rate: 6%
- Years: 1
Final amount 10,600.00
After one year 10,000 × 1.06 = 10,600. Compounding is not visible yet.
Example 5
- Principal: 10,000
- Rate: 6%
- Years: 2
Final amount 11,236.00
Compound vs simple: after 2 years 11,236, not 11,200 from simple interest.
Example 6
- Principal: 10,000
- Rate: 6%
- Years: 10
- Compounding: monthly
Final amount ≈ 18,193.97
Monthly compounding: 10,000 at 6% for 10 years → ≈ 18,193.97.
Example 7
- Principal: 10,000
- Rate: 6%
- Years: 10
- Compounding: monthly
- Contribution: 100 / month
Final amount ≈ 34,581.90
Contributions 12,000
Interest ≈ 12,581.90
Compound interest with 100/month contributions: 10,000, 6%, 10 years → ≈ 34,581.90.
Related calculators
Frequently asked questions
What is a compound interest calculator?
It computes a final amount with principal × (1 + (rate/100)/n)^(n × years). Default n is 1 (yearly). You can choose semiannual, quarterly, monthly, or daily (365) compounding and add a contribution. There is no tax field and no continuous e^(rt) mode.
How is compound interest calculated on this page?
With yearly compounding, the final amount is about 17908.48 and interest is about 7908.48. That is 10000 × 1.06^10.
How do I calculate compound interest with the formula?
Use A = P(1 + r/n)^(n t). On this page r is the annual percent divided by 100, n is periods per year, and t is years. At 10,000, 6%, 10 years, n = 1: 10,000 × 1.06^10 ≈ 17,908.48.
How does monthly compounding work?
The same 10000, 6%, and 10 years give about 18193.97. That is 10000 × (1 + 0.06/12)^120. The effective annual rate is about 6.17%.
Does this include a daily compound interest calculator?
Yes. Choose daily (365) compounding. At 10,000, 6%, and 10 years with monthly compounding the result is about 18,193.97; daily uses n = 365 in the same formula. A separate daily page uses a day count instead of years.
How do contributions work with compound interest?
At 10000, 6%, 10 years, and monthly compounding, the final amount is about 34581.90. Contributions total 12000 and interest is about 12581.90. Each deposit is added at month-end, after that month’s interest.
What is the difference between compound and simple interest?
Simple interest does not add earned interest to principal. After two years, 10,000 at 6% is 11,200 simple versus 11,236 compounded (10,000 × 1.06²). This calculator uses compounding.
Is the result after tax?
No. There is no tax field here. Optional tax on a CD-style term is on the term deposit page.
Is continuous compounding available?
No. Supported n values are 1, 2, 4, 12, or 365. The continuous model e^(rt) is not implemented here.
How is this different from a term deposit?
The term deposit page uses months, a CD compounding menu, optional APY, and an optional tax estimate. This page uses years and has no deposit tax field.
Can I change the monthly contribution amount?
Yes. Under Contribution (optional), enter the amount and leave frequency on monthly. Beginning-of-period timing, inflation, and a target are on the future value page.
Which compounding frequency can I choose?
You choose yearly, semiannual, quarterly, monthly, or daily (365). The default is yearly, so 10000 at 6% for 10 years is 17908.48.
How is savings interest different?
On the savings interest page, the gain is principal × (rate/100) × years, with no compounding. At 10000, 5%, and 3 years you get exactly 1500, not 1.05^3.
Does 6% for 10 years always nearly double?
With yearly compounding 1.06^10 ≈ 1.79, so 10000 at 6% for 10 years is about 17908.48, not 20000. Monthly compounding is about 18193.97.
Do blank years mean 10?
No. You must enter the horizon. The 10 placeholder is a hint.
Knowledge sources
Compound interest in this calculator is the formula from the rate, years, compounding, and optional contribution you enter.
- Wikipedia — compound interest
- Investor.gov — SEC investor education
- Board of Governors of the Federal Reserve System
Page updated September 27, 2026.