How to use the Simple Interest Calculator
- 1. Enter the principalType the amount and the yearly interest rate.
- 2. Add the timeEnter the number and choose years, months or days.
- 3. See the interestGet the interest, the total and how compounding would compare.
The simple interest formula
SI = P × R × T ÷ 100
P is the principal. R is the rate per year in percent. T is the time in years. The total you pay or receive is P + SI.
Worked example: ₹1,00,000 at 8% for 3 years. SI = 1,00,000 × 8 × 3 ÷ 100 = ₹24,000, and the total is ₹1,24,000. The interest is the same ₹8,000 each year, since it is always worked out on the original amount.
When time is not in years
The formula needs time in years, so convert first. This calculator does it for you.
- Months. Divide by 12. For 6 months on ₹1,00,000 at 8%, SI is ₹4,000.
- Days. Divide by 365. For 73 days on the same sum, SI is ₹1,600.
Some lenders use a different day count, so a real statement can differ by a small amount.
Where simple interest is used
You will see it in school and competitive exam sums, and in many informal loans between people. Some short-term loans and overdue charges are also worked out this way. Always ask a lender how interest is calculated, as many quote a flat rate that costs more than it sounds.
The result also shows what the same terms would earn if compounded yearly. For our example that is ₹25,971 against ₹24,000. The gap grows quickly with longer terms. Try the compound interest calculator to explore that gap. For income paid out without compounding, see how the SCSS calculator works.
Frequently asked questions
Is the rate per year or per month?
Enter the yearly rate. If you have a monthly rate, such as 2% a month, multiply by 12 and enter 24%.
How do I find the total amount?
Add the interest to the principal. The calculator shows this as Total amount.
Why does the table not always appear?
The yearly table shows up only when the time is 2 years or more. For shorter times, the interest and total are enough.
Is the simple interest calculator free?
Yes. You enter your name and WhatsApp number once to see your result, and all other Uncodemy tools then open without the form.