A fast, free, offline Android app for calculating simple and compound interest. Built for shopkeepers, lenders, students, and anyone who needs accurate interest figures in seconds — in English or Hindi.
Everything you need for everyday interest calculations.
Switch between simple and compound interest with a single tap. Monthly-compounded results match traditional Indian byaj practice.
Enter time in years, months, and days. The app handles partial periods accurately for both interest types.
Results are displayed in the Indian numbering system (lakhs and crores) with proper currency formatting.
Full interface translation in English and Hindi. Switch from the overflow menu — your choice is remembered next time.
Share calculated interest details over WhatsApp, SMS, or any other app. Great for quoting customers or keeping records.
No internet required for calculations. Your inputs never leave your device. The only network use is for showing ads.
Three taps. That's it.
Type the amount you want to calculate interest on. The app auto-formats it in the Indian numbering system as you type.
Choose years, months, and days from the dropdowns. Enter the annual rate of interest. Pick simple or compound.
Tap Calculate to see the interest amount and total amount. Hit Share to send the breakdown to anyone.
Switch anytime from the overflow menu.
A small utility, built and maintained by an independent developer.
Byaj Calculator was built to make everyday interest math frictionless — the kind of calculation shopkeepers, family lenders, and students need to do often, on paper or on a phone. It runs entirely on-device, asks for no personal data, and weighs in under a megabyte.
It is free to use and supported by Google AdMob ads. For details on what data the advertising SDK collects, see the Privacy Policy.