Simple Interest Calculator
Linear interest on an initial amount.
Final amount
$2,240.00
- Interest
- $240.00
- Initial capital
- $2,000.00
How it works
Simple interest is always computed on the original principal — no interest on interest. Common in late-payment fees, short contracts and some legacy loans.
Formula:
I = P × r × t M = P + I
Practical examples
$2,000 at 2%/mo for 6 months
I = 2000 × 0.02 × 6 = $240. M = $2,240.
$500 at 1.5%/mo for 10 months
I = 500 × 0.015 × 10 = $75. M = $575.
Late fee
$800 at 2%/mo for 3 months accrues $48 in interest.
Frequently asked questions
When should I use simple interest?
For late fees, short contracts or legal calculations. Most investments and loans use compound interest.
Do rate and time units need to match?
Yes. Monthly rate → time in months. This calculator uses months.
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⚠️ Disclaimer
This calculator is for educational and informational purposes only. Results are estimates based on public formulas and may contain inaccuracies or be outdated. We are not accountants, lawyers, doctors, or financial advisors — for any important decision (tax filings, contracts, diagnoses, financial planning), always consult a qualified professional. calculadora.work assumes no liability for decisions made based on the content of this site.