$100 Invested at 8% for 3 Years
$127.02
Future Value (compounded monthly)
$100 invested at 8% annual compound interest (compounded monthly) for 3 years will grow to $127.02. You earn $27.02 in interest. At 8%, your money doubles in approximately 9 years (Rule of 72).
Year-by-Year Growth
| Year | Balance | Interest |
|---|---|---|
| 1 | $108.30 | $8.30 |
| 2 | $117.29 | $17.29 |
| 3 | $127.02 | $27.02 |
Quick Reference Table
| Principal | Rate | Years | Future Value |
|---|---|---|---|
| $100 | 6% | 3 yrs | $119.67 |
| $100 | 7% | 3 yrs | $123.29 |
| $100 | 9% | 3 yrs | $130.86 |
| $100 | 10% | 3 yrs | $134.82 |
| $100 | 8% | 1 yrs | $108.30 |
| $100 | 8% | 2 yrs | $117.29 |
| $100 | 8% | 5 yrs | $148.98 |
| $100 | 8% | 7 yrs | $174.74 |
| $100 | 8% | 10 yrs | $221.96 |
| $100 | 8% | 15 yrs | $330.69 |
Formula Used
A = P(1 + r/n)nt
- P = $100
- r = 8% = 0.08
- n = 12 (monthly)
- t = 3 years
- A = $127.02
Frequently Asked Questions
How much will $100 grow at 8% compound interest in 3 years?
$100 grows to $127.02. Interest earned: $27.02.
How long to double $100 at 8%?
Using the Rule of 72: 72 ÷ 8 ≈ 9 years.
What is the compound interest formula?
A = P(1 + r/n)^(nt). P=$100, r=8%=0.08, n=12, t=3.