Free Calculators Online
Financial calculators (EMI, tax, GST, tip, currency), health calculators (BMI, age), and everyday math tools. Each result includes the formula used so you can verify the calculation.
7 free tools — browser-based, no sign-up required.
BMI Calculator
Calculate your Body Mass Index
Age Calculator
Calculate exact age from date of birth
EMI Calculator
Calculate loan EMI payments
Tax Calculator
Calculate income tax estimates
GST Calculator
Calculate GST amounts
Percentage Calculator
Calculate percentages easily
Tip Calculator
Calculate tips for dining
About FlexyPdf Calculators
Calculator tools are the digital equivalent of the back of an envelope — most of the time you just need a quick answer, not a spreadsheet model. The calculators here are tuned for that: type the inputs, see the result, see the formula used to get there. Every numeric output is reproducible by hand, which matters because most people use these calculators to sanity-check something a bank, an HR portal, or a tax form has already produced.
The financial calculators handle the formats people actually deal with in everyday life. The EMI calculator supports both reducing-balance (the standard for home and car loans in most countries) and flat-rate interest, with an amortization schedule that shows principal vs interest for each month — useful for understanding why your early payments barely touch the principal. The tax calculator handles tiered tax brackets for several regions; the GST calculator includes inclusive and exclusive modes with rate presets for common jurisdictions.
The health calculators are reference tools rather than medical advice. The BMI calculator uses the standard WHO formula and shows category breakdowns, with a note that BMI is a population-level metric and does not account for muscle mass. The age calculator returns the precise age in years, months, and days as of a chosen date, useful for forms and applications that demand it. The currency converter pulls live exchange rates from a public API and shows the timestamp of the last update.
Who uses these tools
A few of the recurring use cases we hear about from FlexyPdf visitors.
People comparing loan offers
Calculating the true monthly payment for different loan amounts and tenures, seeing how a small interest rate difference compounds over 20 years.
Freelancers and small business owners
Computing GST/VAT on invoices, calculating tax on quarterly income, splitting a restaurant bill with a tip.
Travellers and shoppers
Converting prices between currencies, calculating tip amounts in different cultural contexts.
Students and parents
Quick BMI checks, calculating exact age for school applications, working through math homework problems with a visible formula.
Frequently asked questions
How often is the currency exchange rate updated?
The converter fetches rates from a public exchange rate API and the response is cached for one hour. The timestamp of the last fetch is shown next to the conversion result.
Are the tax calculators accurate for my country?
The tax calculator supports tiered brackets for several specific regions (each labelled explicitly). It is intended as a quick estimate, not a tax filing tool — always verify against official tax authority calculators for legal purposes.
Why does the EMI total interest seem so high?
On a typical home loan, interest accumulates on the outstanding balance, which is highest at the start of the loan. Over a 20-year tenure, total interest paid often equals or exceeds the principal. The amortization schedule shows exactly how this breaks down month by month.