Simple interest
Simple interest is calculated only on the original principal, so growth is linear.
SIMPLE VS COMPOUND
Interest Calculator
Calculate interest and compare simple growth with compound growth.
YOUR INPUTS
COMPOUND RESULT120 months
$16,470.09
Final balance$16,470.09
Total contributions$10,000.00
Simple-interest balance$15,000.00
Estimated fees$0.00
BALANCE OVER TIME$16,470
YEAR-BY-YEAR
| Period | Final balance | Total contributions | Growth / interest |
|---|---|---|---|
| 12 months | $10,511.62 | $10,000.00 | $511.62 |
| 24 months | $11,049.41 | $10,000.00 | $1,049.41 |
| 36 months | $11,614.72 | $10,000.00 | $1,614.72 |
| 48 months | $12,208.95 | $10,000.00 | $2,208.95 |
| 60 months | $12,833.59 | $10,000.00 | $2,833.59 |
| 72 months | $13,490.18 | $10,000.00 | $3,490.18 |
| 84 months | $14,180.36 | $10,000.00 | $4,180.36 |
| 96 months | $14,905.85 | $10,000.00 | $4,905.85 |
| 108 months | $15,668.47 | $10,000.00 | $5,668.47 |
| 120 months | $16,470.09 | $10,000.00 | $6,470.09 |
Compound interest
Compound interest adds earned interest to the base used for future calculations.
Where each appears
Savings commonly compound. Some short-term lending uses simple interest, but fees and amortization can change real borrowing costs.
How the Interest Calculator works
Calculations run entirely in your browser. We apply the formulas shown above to a month-by-month schedule, hold your entered rate constant, and treat every result as an estimate—not a forecast or bank quote.
FREQUENTLY ASKED QUESTIONS
Clear answers. Better inputs.
Which produces more interest?+
With a positive rate and enough time, compound interest exceeds simple interest on the same principal.
Does frequency matter?+
At the same nominal rate, a higher frequency generally raises the effective annual yield slightly.
Can I use this for loans?+
Only for a rough interest comparison. It does not model payment schedules, fees, or amortization.