Simple Interest Calculator
Interest and total amount with simple interest.
How it works
Interest = P × r ÷ 100 × t
Simple interest accrues only on the principal; earned interest does not compound. Common for short-term loans.
FAQ
Simple vs compound interest?
Simple uses only the principal; compound adds each period’s interest back, so it grows faster over time.
Worked example
Principal 100,000 at 4% for 3 years:
interest = 100000 × 4% × 3 = 12,000, total 112,000.
Compound interest gives 112,486 — 486 more; over 30 years the gap is about 24,000.
Notes and limitations
Simple interest is common in short consumer loans and some advertised yield figures. When you see "4% a year", confirm simple versus compound and whether fees are included.