Interest Rate Calculator
Find the annual interest rate on any investment or loan using principal, interest earned, and time. Instant results with detailed breakdown charts and shareable links.
About This Calculator
Our Interest Rate Calculator helps you determine the annual interest rate on any financial product, whether you are investing money or taking out a loan. Simply provide the principal amount, the total interest earned or final amount received, and the time period to get your annual rate instantly. This tool is ideal for investors evaluating fixed deposits, bonds, or savings accounts, as well as borrowers comparing loan offers to understand the true cost of borrowing.
The calculator applies the standard simple interest formula: Rate = (Interest / (Principal x Time)) x 100. This gives you the effective annual interest rate as a percentage, allowing you to compare different financial products on a consistent basis. For example, if you invested ₹10,000 and earned ₹2,000 over 3 years, your annual interest rate would be (2000 / (10000 x 3)) x 100 = 6.67% per year. The results include a full breakdown of principal, interest, and total amount, plus interactive bar and pie charts for visual analysis.
The Interest Rate Calculator works in two modes. In Interest Amount mode, enter the principal and the total interest earned or paid. In Total Amount mode, enter the principal and the final total (principal plus interest). Both modes calculate the same annual interest rate using the same formula, just from different starting data. Note that this calculator uses simple interest — for compound interest rate calculations, please use our dedicated Compound Interest Calculator instead.
Regional Notes
India: Savings account rates typically range 2.5-4%, fixed deposits 5-7.5%, and loan rates vary from 8-15% depending on the type and lender. Use this calculator to find the effective rate on any instrument across Indian banks and NBFCs.
US: High-yield savings accounts offer 4-5% APY, while mortgage rates range from 6-8% and personal loans from 7-36%. Use this tool to compute the actual rate you are earning or paying on any US financial product.
UK: Easy-access savings accounts pay 2-4%, fixed-rate bonds offer 3-5%, and mortgage rates are typically 4-6%. Enter your numbers to see your personalised annual interest rate for any UK investment or loan.
Frequently Asked Questions
How does the Interest Rate Calculator work?
Enter your principal amount, the interest earned or total amount received, and the time period in years. The calculator uses the simple interest formula to determine the annual interest rate: Rate = (Interest / (Principal x Time)) x 100.
Can I use this calculator for both investments and loans?
Yes, the Interest Rate Calculator works for both investments and loans. For investments, enter how much you invested and the total returns to find your annual return rate. For loans, enter the loan amount and total payments to find the effective interest rate you are being charged.
What is the difference between the Interest Amount and Total Amount modes?
In Interest Amount mode, you enter the principal and the total interest earned or paid. In Total Amount mode, you enter the principal and the final total (principal plus interest). Both modes calculate the same annual interest rate, just from different starting data.
How do savings account interest rates compare in India, US, and UK?
Savings account interest rates vary by country. In India, savings accounts typically offer 2.5% to 4% per annum. In the US, rates range from 0.1% for traditional accounts to 4-5% for high-yield savings accounts. In the UK, easy-access accounts offer around 2-4% depending on the provider and Bank of England base rate.
What is a good annual interest rate for a fixed deposit in India?
Fixed deposit interest rates in India vary by bank and tenure. As of 2025, leading banks offer FD rates between 5% and 7.5% per annum, with small finance banks offering up to 8.5%. Senior citizens typically receive 0.25% to 0.75% higher rates. Locking in for longer tenures usually yields better rates.
Does this calculator use simple interest or compound interest?
This calculator uses the simple interest formula, which calculates the annual interest rate as a proportion of the original principal over the total time period. For compound interest calculations where interest earns interest over time, use our Compound Interest Calculator instead.
Can I share my interest rate calculation results?
Yes, all your input values are saved in the URL, so you can copy the page URL and share it with anyone. When they open the link, the calculator will automatically load your numbers and show the same results.