Interest Calculator
Calculate simple interest and maturity value from principal, rate and term.
How to use Interest Calculator
Uses simple interest by multiplying principal, annual rate and term. Results are before tax and exclude fees and institution-specific day-count rules.
Displayed values follow the definitions stated above.
How to read a simple-interest result
Simple interest applies the same rate to the original principal in every period. It is useful for quick comparisons, but you should still check whether the real product compounds and whether taxes or fees apply.
Maturity value equals the principal plus the calculated interest.
Recommended steps
- Enter only the amount that actually earns interest.
- Use an annual rate rather than a monthly rate.
- Convert months to years by dividing the number of months by 12.
How to interpret the result
- The result is before tax and may differ from the amount received.
- Compound interest grows faster than simple interest as the term becomes longer.
- Product rules for early withdrawal and day counts take priority.
Frequently asked questions
What is the difference between simple and compound interest?
Simple interest is calculated only on the original principal. Compound interest also earns interest on earlier interest.
How do I enter a six-month term?
Enter 0.5 years. Three months is 0.25 years and 18 months is 1.5 years.
Does the result include tax?
No. It is a before-tax estimate and excludes withholding tax, promotional conditions and fees.