How this calculation works
Simple interest does not earn interest on previous interest. The same principal produces an equal interest amount each year when the rate remains constant.
Interest = principal × annual rate × years ÷ 100A worked example
₹1,00,000 at 8% simple interest for 5 years earns ₹40,000.
Good to know
A planning estimate. Actual products may use different payment dates, fees, tax treatment or rounding. Rates entered here are assumptions, not offers.
Equal time adds equal interest
At a fixed 8% simple rate on ₹1,00,000, each full year adds ₹8,000. After one year the interest is ₹8,000; after five it is ₹40,000. The growing total never becomes the new interest-bearing principal in this model.
That straight-line pattern is the defining feature of simple interest. A graph of interest against time is a straight line when principal and rate are constant. Compound interest instead changes the interest-bearing base, so the two models increasingly diverge over longer periods.
Check what the quoted time unit means
A percentage and a time period must use matching units. This tool takes an annual percentage rate and years. Six months corresponds to 0.5 years. Do not enter 6 expecting it to mean six months; that would model six full years.
Actual agreements may calculate fractions of a year using different day-count conventions. A period described as 90 days is not automatically one quarter of every calendar year. Read the contract’s convention if an exact settlement amount matters.
Where this estimate is useful
Use it to understand a clearly stated simple-interest arrangement, compare the interest component of an illustration, or check a classroom example. Enter the original principal and keep the rate unchanged if you are comparing only the effect of time.
Do not use a simple-interest total as a substitute for an amortizing-loan schedule. If principal is repaid during the term, the interest-bearing balance changes, and the calculation must reflect those repayments.
A few questions, answered
Does interest earn more interest here?
No. Only the starting principal earns interest in this model.
Why does the interest double when the time doubles?
With principal and rate unchanged, simple interest is proportional to time. Twice the time means twice the interest.