Simple interest calculator
Interest on savings or a debt over days, months or years, without compounding.
How it works
Interest = principal × rate × time (in years). For a duration in days: principal × rate × days ÷ 365 (or 360). Unlike compound interest, the interest earned does not earn interest itself.
Results are for guidance only and do not replace professional advice.
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Worked example
With the default values:
- Principal5000
- Annual rate (%)3
- Duration18
- UnitMonths
- Day count basis365 days (actual)
you get:
- Interest€225.00
- Final amount€5,225.00
- Duration in years1.5
- Interest per month€12.50
Frequently asked questions
How does the “Simple interest calculator” tool work?
Interest = principal × rate × time (in years). For a duration in days: principal × rate × days ÷ 365 (or 360). Unlike compound interest, the interest earned does not earn interest itself.
What do I need to enter?
Just fill in: principal, annual rate, duration, unit, day count basis. The result updates as you type.
Can you give an example?
Principal: 5000; Annual rate (%): 3; Duration: 18; Unit: Months; Day count basis: 365 days (actual) → Interest: €225.00; Final amount: €5,225.00.
Is this calculator free, and is my data private?
Yes. HOD Calc is completely free with no sign-up. The calculation runs in your browser: nothing you type is sent or stored.