Financial Mathematics Engine

Simple Interest Calculator Online

Calculate simple interest on personal loans, promissory notes, agricultural loans, or gold finance, and compare the result directly against compound growth.

Calculating simple interest…

Enter Loan / Investment Details

The initial sum of money borrowed or lent.
Annual rate charged or earned on principal.
Full completed years of loan duration.
Extra months added to the total term.
Year Opening Principal Simple Interest Total SI Accrued Compound Value (Annual)

Principal vs Simple Interest vs Compound Variance

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How Simple Interest Works in Financial Transactions

Simple interest is determined solely by multiplying the daily or annual interest rate by the principal amount and the number of days or years that elapse. The classic equation is SI = (P × R × T) / 100, where P is the initial principal, R is the annual interest rate, and T is the duration in years.

Simple Interest vs Compound Interest

In simple interest contracts, the interest earned or owed in Year 1 is identical to the interest in Year 5 because the principal remains flat. Under compound interest, unpaid interest is added back into the principal at each interval (annual, semi-annual, or quarterly), compounding the total sum exponentially over longer tenures.

Frequently Asked Questions

Can simple interest be computed for daily or monthly loans?

Yes. For monthly loans, time T is expressed as Months / 12. For daily interest calculations, time is expressed as Days / 365.

Do Indian banks offer simple interest on Fixed Deposits?

Bank fixed deposits with tenures below 6 months generally use simple interest calculated on a daily product basis. Deposits of 6 months or longer compound interest on a quarterly basis.

Is simple interest better for a borrower?

Yes. For a borrower, simple interest is always more economical than compound interest because you never pay interest on accumulated interest.