Simple interest calculator
Calculate interest on the original principal only.
Formula
Interest = principal × annual rate / 100 × years; total = principal + interest
Simple interest ≈ (1,000)×(5)÷100×(2) · Principal plus interest ≈ (1,000)+(100)
How to use
- Enter the starting principal.
- Enter annual rate and years; 0.5 means six months.
- Read interest and principal plus interest.
Examples
- 4,000 at 5.5% for 4 years earns 880.
- 1,000 at 6% for half a year earns 30.
Frequently asked questions
Does interest earn interest?
No. The calculation always uses the original principal.
How do I enter months?
Divide months by 12; six months is 0.5 years.
Does this model monthly repayments?
No. It assumes the principal stays unchanged during the term.
Sources
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