Calculate simple interest using SI = P × R × T ÷ 100. Supports years, months, days, and multiple currencies. Free global simple interest calculator.
Step-by-step guide to get the most from this tool
Choose INR, USD, EUR, or GBP for your calculation.
Set the loan or investment amount and annual interest rate.
Enter duration in years, months, or days.
See simple interest, total amount, formula breakdown, and interest growth chart.
What makes this tool stand out
INR, USD, EUR, and GBP support.
See the exact SI calculation breakdown.
Years, months, or days.
Visualize interest accumulation over time.
Live calculation as you type.
No signup, works worldwide.
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Quick answers to common questions
Simple interest is calculated only on the principal amount, not on accumulated interest. Formula: SI = P × R × T ÷ 100, where P is principal, R is annual rate (%), and T is time in years.
Simple interest stays constant each period. Compound interest earns interest on interest, growing faster over time. Use our Compound Interest Calculator to compare both.
Yes. Select months or days as the time unit. The calculator converts to years automatically (months ÷ 12, days ÷ 365).
Simple interest is common in short-term personal loans, some car loans, student loans, and bonds. Many Indian microfinance and informal loans use simple interest.
Our calculator supports INR (₹), USD ($), EUR (€), and GBP (£). Select your currency from the dropdown before entering amounts.
Yes. Simple interest results in lower total interest than compound interest for the same rate and period, making it cheaper for borrowers.
Multiply monthly rate by 12 for approximate annual rate. For precise calculations, use the annual rate directly in this calculator.
For compound interest, money doubles in approximately 72 ÷ rate years. Simple interest does not follow this rule since interest does not compound.
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