Free Online Calculators: GST, EMI, Percentage, Age and BMI

Quick answers to the maths that comes up in real life: how much GST is inside a bill, what your loan EMI will be, how old you are on a cut-off date. These free online calculators show the formula next to the answer, so you can check the working instead of trusting a number.

Money and tax calculators

GST CalculatorAdd or remove GST at the new 5%, 18% and 40% rates, with the CGST and SGST split.New EMI CalculatorMonthly instalment, total interest and payment schedule for home, car or personal loans.Loans Compound Interest CalculatorSee how savings and investments grow with compounding over time.Savings Percentage CalculatorPercent of a number, percentage change, discounts and reverse percentages.Maths Currency ConverterConvert between major currencies such as INR, USD, EUR and GBP.Money

Health and date calculators

Age CalculatorExact age in years, months and days on any date, handy for exam age limits.Dates BMI CalculatorBody mass index with both standard and Asian/Indian cut-offs.Health

Guides that explain the maths

How to calculate percentage: formulas and shortcuts with worked examples.
EMI formula explained: how banks work out your monthly payment.
Compound interest formula: why starting early matters.

Frequently asked questions

Are these calculators accurate?

They use the standard formulas, which are shown with each result so you can check them. For tax filing or loan agreements, confirm the final figures with your bank, lender or a tax professional.

Do the calculators save my data?

No. The numbers you type stay in your browser and are not stored.

Which GST rates does the GST calculator use?

The current GST 2.0 slabs of 5%, 18% and 40%, plus 3% for gold and silver. It also keeps the old 12% and 28% rates for checking invoices dated before 22 September 2025.

More free tool collections

All tools on FreeToolsLand are free, work in your browser and need no sign-up. Read how we build and test our tools.