Interest Calculators
Simple Interest Calculator
Calculate simple interest, where interest is charged only on the original amount and never on interest already accrued.
Total interest
$1,500
- Final amount
- $11,500
- Interest per year
- $500
Yr 1Yr 2Yr 3
How this calculator works
I = P × r × t
- P
- the principal
- r
- the annual rate as a decimal
- t
- the time in years
Important considerations
- Most consumer borrowing compounds instead, which costs more.
- Part years are treated proportionally.
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- Loan Interest CalculatorTotal interest cost across the life of a loan.
- Effective Interest Rate CalculatorEffective annual rate for any compounding frequency.
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Learn more
Terms used here
Frequently asked questions
Where is simple interest actually used?
Short-term notes, some car finance and many bonds pay simple interest on the face amount.
Disclaimer
Legamoney calculators are educational tools. Results are estimates based on the figures you enter and do not constitute financial, tax or legal advice.
Last reviewed 2026-08-01