INVESTING CALCULATOR

Compound Interest Calculator

Estimate how your investments could grow over time.

Your investment details

Adjust the values below, then calculate your estimate.

Calculations happen in your browser. No information is collected or saved.

ESTIMATED FUTURE VALUE

$300,850.72

after 20 years

Total Contributions$130,000.00
Investment Growth$170,850.72
Portfolio valueContributions
$0$75.2K$150.4K$225.6K$300.9KTodayYear 5Year 10Year 15Year 20Year 0: Portfolio value $10,000.00, total contributions $10,000.00Year 1: Portfolio value $16,919.19, total contributions $16,000.00Year 2: Portfolio value $24,338.58, total contributions $22,000.00Year 3: Portfolio value $32,294.31, total contributions $28,000.00Year 4: Portfolio value $40,825.16, total contributions $34,000.00Year 5: Portfolio value $49,972.70, total contributions $40,000.00Year 6: Portfolio value $59,781.53, total contributions $46,000.00Year 7: Portfolio value $70,299.43, total contributions $52,000.00Year 8: Portfolio value $81,577.68, total contributions $58,000.00Year 9: Portfolio value $93,671.22, total contributions $64,000.00Year 10: Portfolio value $106,639.02, total contributions $70,000.00Year 11: Portfolio value $120,544.25, total contributions $76,000.00Year 12: Portfolio value $135,454.70, total contributions $82,000.00Year 13: Portfolio value $151,443.02, total contributions $88,000.00Year 14: Portfolio value $168,587.14, total contributions $94,000.00Year 15: Portfolio value $186,970.62, total contributions $100,000.00Year 16: Portfolio value $206,683.03, total contributions $106,000.00Year 17: Portfolio value $227,820.45, total contributions $112,000.00Year 18: Portfolio value $250,485.91, total contributions $118,000.00Year 19: Portfolio value $274,789.85, total contributions $124,000.00Year 20: Portfolio value $300,850.72, total contributions $130,000.00

How to Use This Calculator

  1. Enter your starting investment.
  2. Add the amount you plan to contribute each month.
  3. Choose an estimated annual return, time period, and compounding frequency.
  4. Select Calculate to update the results.

Year-by-Year Breakdown

See how contributions and estimated growth build over time.

YearStarting BalanceAnnual ContributionsInterest EarnedEnding Balance
1$10,000.00$6,000.00$919.19$16,919.19
2$16,919.19$6,000.00$1,419.38$24,338.58
3$24,338.58$6,000.00$1,955.73$32,294.31
4$32,294.31$6,000.00$2,530.85$40,825.16
5$40,825.16$6,000.00$3,147.55$49,972.70
6$49,972.70$6,000.00$3,808.82$59,781.53
7$59,781.53$6,000.00$4,517.90$70,299.43
8$70,299.43$6,000.00$5,278.24$81,577.68
9$81,577.68$6,000.00$6,093.55$93,671.22
10$93,671.22$6,000.00$6,967.79$106,639.02
11$106,639.02$6,000.00$7,905.24$120,544.25
12$120,544.25$6,000.00$8,910.45$135,454.70
13$135,454.70$6,000.00$9,988.32$151,443.02
14$151,443.02$6,000.00$11,144.12$168,587.14
15$168,587.14$6,000.00$12,383.47$186,970.62
16$186,970.62$6,000.00$13,712.41$206,683.03
17$206,683.03$6,000.00$15,137.43$227,820.45
18$227,820.45$6,000.00$16,665.45$250,485.91
19$250,485.91$6,000.00$18,303.94$274,789.85
20$274,789.85$6,000.00$20,060.87$300,850.72

How Compound Interest Works

Compound interest means earning returns on both your original investment and the returns already added to it. Regular contributions and more time can make compounding increasingly powerful, but actual market returns will vary.

Calculation Assumptions

  • Monthly contributions are made at the end of each month.
  • The annual return remains constant.
  • Taxes, fees, inflation, and market volatility are excluded.
  • Results are educational estimates, not financial advice.

Frequently Asked Questions

What annual return should I use?

A conservative estimate is usually more useful than an optimistic one. Historical market performance does not guarantee future returns.

Does compounding frequency make a difference?

Yes. More frequent compounding can modestly increase the result when the stated annual rate is the same.

Are monthly contributions included?

Yes. The calculator assumes each monthly contribution is added at the end of the month.

Does this account for inflation or taxes?

No. The estimate excludes inflation, taxes, investment fees, and market volatility.