Compound Interest Calculator
Watch your money compound — with regular contributions.
Value after 20 years
$300,850.72
- Total contributed
- $130,000.00
- Interest earned
- $170,850.72
- Multiple of contributions
- 2.31×
| Year | Contributed | Balance |
|---|---|---|
| 1 | $6,500.00 | $16,919.19 |
| 2 | $13,000.00 | $24,338.58 |
| 3 | $19,500.00 | $32,294.31 |
| 4 | $26,000.00 | $40,825.16 |
| 5 | $32,500.00 | $49,972.70 |
| 6 | $39,000.00 | $59,781.53 |
| 7 | $45,500.00 | $70,299.43 |
| 8 | $52,000.00 | $81,577.68 |
| 9 | $58,500.00 | $93,671.22 |
| 10 | $65,000.00 | $106,639.02 |
| 11 | $71,500.00 | $120,544.25 |
| 12 | $78,000.00 | $135,454.70 |
| 13 | $84,500.00 | $151,443.02 |
| 14 | $91,000.00 | $168,587.14 |
| 15 | $97,500.00 | $186,970.62 |
| 16 | $104,000.00 | $206,683.03 |
| 17 | $110,500.00 | $227,820.45 |
| 18 | $117,000.00 | $250,485.91 |
| 19 | $123,500.00 | $274,789.85 |
| 20 | $130,000.00 | $300,850.72 |
About this calc
See the final value of your investment after compounding. Add monthly contributions to model a real savings plan. Results show total interest and total contributed.
FAQ
- What's the compound interest formula?
- A = P(1 + r/n)^(nt) where P is principal, r is annual rate, n is compounding periods per year, and t is years. Regular contributions add a future-value-of-annuity term.
- Does compounding frequency matter much?
- Usually only a little. Monthly vs annual on a 7% / 20-year plan differs by ~2–3%. Contributions and time matter way more than compounding frequency.
- What rate should I use for investments?
- Historical stock-market average is ~7% real (after inflation). For conservative planning, use 5–6%. For high-yield savings, use the current APY (often 4–5% in 2026).