Simple Interest Calculator
Calculate simple interest and total from principal, rate, and time. Example: $1000, 5% per year, 3 years → $150 interest, $1150 total. Copy result.
Simple interest is I = P × r × t: principal × rate (as decimal) × time. Enter principal, annual rate (%), and time (years). The calculator gives interest and total. No compounding. Copy the result or Copy with labels.
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Examples
- $1000, 5% per year, 3 years → $150 interest, $1150 total
- €5000, 4% per year, 2 years → €400 interest, €5400 total
- $10000, 6% per year, 6 months → $300 interest (t = 0.5)
FAQ
What is simple interest?
Interest = principal × rate × time. No compounding. Interest is not added to the principal for future periods.
What is the formula?
I = P × r × t (rate as decimal, e.g. 5% = 0.05). Total = P + I.
What time unit can I use?
Use years, months, or days. Ensure the rate matches (e.g. annual rate with years).
How is this different from compound interest?
Simple interest: interest only on principal. Compound: interest on principal plus prior interest.
What currency?
Enter principal in your currency. Result is in the same unit.