Simple Interest Calculator
Simple interest with exact principal, rate and years plus months
Key Features & Calculation Guidance
Key features: Exact Inputs, Years + Months, Flat-Rate Warning. Free, 100% browser-based — no login required.
Frequently Asked Questions
Can I calculate simple interest for months?
Yes. Enter completed years and additional months. The calculator converts the months into a fraction of a year before applying the simple-interest formula.
Is a 10% flat loan the same as a 10% reducing-balance loan?
No. With a flat-rate loan, interest can be calculated on the original principal for the full tenure even as instalments are repaid. A reducing-balance loan calculates interest on the outstanding principal, so headline rates are not directly comparable.
Does simple interest compound?
No. Interest is calculated on the original principal only; previously accrued interest does not itself earn interest in this model.
Trending Financial Searches in India
Last updated: 2026-09-04
- Old vs New Tax Regime FY 2026-27 Slabs — Zero tax limit applies up to ₹12.75 Lakhs gross salary under New Regime with ₹75,000 standard deduction.
- Best Personal Loan Interest Rates in 2026-27 — Look for personal loan interest rates starting as low as 8.5% to save more on repayments.
- Top Equity Mutual Funds to Invest in FY 2026-27 — Consider allocating 30% of your portfolio to equity mutual funds that have consistently generated returns above 12% annually for 5 years.
- How to Plan for Retirement in 2026-27 — Aim to save at least 15% of your income annually and invest it in NPS or PPF for a secure retirement.