What this site is
CalcTortoise is an independent website of money calculators. The India version has 45calculators covering loans, investments, tax and the government's small savings schemes, in English and Hindi. The US version and the global version (any currency) have their own calculators, written to each country's rules. More are added a few at a time.
Every calculator is free, needs no sign-up and runs entirely in your browser. You can share your figures as a link, download the yearly table as a CSV file or print the page as a PDF.
How we keep the numbers right
- Each calculator uses the standard formula banks and the government use, and is tested against worked examples before its page goes live.
- Every number written in a page's text is worked out by the calculator itself, so the explanations always match the results.
- Scheme rules come first from the official texts: the scheme notifications of December 2019 made under the Government Savings Promotion Act, 1873, the amendments issued since, and the Income-tax Act, 2025. Where a website says something different, we follow the official text and say so on the page.
- Interest rates for government schemes are revised every quarter. Each scheme page shows the quarter its rate applies to.
The full details are on the How we calculate page.
Who is behind it
The pages are written by the CalcTortoise editorial team and each new calculator is reviewed by the site owner before it goes live. Read our editorial policy for how we choose sources, check numbers and fix mistakes, and how we use AI.
Who runs it
CalcTortoise is operated by KRD Technologies, India.
Independence
This site is not run by, linked to or endorsed by the Government of India, India Post, the Reserve Bank of India or any bank, fund house or lender.
How the site is paid for
The site is free to use. It shows no advertising and no affiliate links today. If that changes, ads and paid links will be clearly labelled, will never change how any calculator works, and this page and the privacy policy will be updated first.
Found a mistake?
Please tell us through the contact page. Corrections are listed, with dates, in the corrections log.
Last updated .