Simple Interest Calculator
Calculate simple interest to understand basic interest calculations. See how interest grows linearly over time and compare with compound interest.
Enter the initial amount
Enter the annual interest rate as a percentage
How long you want to calculate interest for
Select the unit for the time period
Advanced Options
How to calculate daily interest
Total Interest
Final Amount
Principal
Important Assumptions
This calculator uses standard simple interest formulas and assumes consistent interest rates throughout the calculation period.
It does not account for variable interest rates, fees, penalties, or early withdrawal charges.
Simple interest calculations are linear and do not compound.
For accurate financial planning, consult with financial institutions for actual terms and conditions.
Frequently Asked Questions
Simple interest grows linearly: Interest = Principal × Rate × Time. Time can be in years, months, or days (using 365/360 conventions).