Everyday CalculatorsFree browser tools
Five everyday calculators

Numbers,
Answered Fast

Fast, free everyday calculators — no app installs, no signups. Work out a percentage, a monthly loan payment, your BMI, your exact age, or how to split the check, all in your browser.

View CalculatorsWhy use these

Everyday Calculators

The five calculations people actually reach for.

Privacy: On-Device

Percentage Calculator

Percent of a number, one number as a percent of another, and percentage change.

Open Utility

BMI Calculator

Body mass index in metric or imperial units with the WHO category ranges.

Open Utility

Loan Calculator

Monthly payment, total repaid, and total interest for any fixed-rate loan.

Open Utility

Age Calculator

Exact age in years, months, and days plus the countdown to your next birthday.

Open Utility

Tip Calculator

Tip amount, grand total, and the per-person share when you split the bill.

Open Utility

Why Use an Online Calculator?

A phone calculator can add and multiply, but it will not tell you what a 4.9% loan actually costs over five years, or how many days old you are. These tools wrap the formula around the arithmetic so you only have to supply the numbers you already know.

The formula is shown, not hidden

Each calculator displays the expression it evaluated alongside the answer. That makes the result checkable — useful for homework, for double-checking a lender's quote, and for learning the method rather than just trusting a black box.

Sensitive numbers stay yours

Salaries, debt balances, weights, and birthdates are personal. None of it is transmitted anywhere: the page is a static document and the maths runs in your own browser tab, so there is no server log to worry about.

Built for quick answers

There is no "calculate" wait state and no page reload. Results update as you type, so you can drag a rate up and down and watch the monthly payment respond immediately.

Honest about limits

A loan estimate excludes fees and insurance; BMI ignores muscle mass. Every page says so plainly instead of presenting a single number as the final word.

Frequently asked questions

Are these calculators free to use?

Yes. Every calculator on this site is completely free with no usage limits, no trial period, and no premium tier. The site is funded by non-intrusive advertising so the tools can stay free.

Do the calculations happen on a server?

No. Every formula runs in your browser using plain JavaScript. Nothing you type — not a salary, not a loan balance, not a date of birth — is ever sent to us or stored anywhere.

Do I need to install an app or create an account?

Neither. Open a calculator and start typing. There is no sign-up form, no email verification, and no download of any kind.

How accurate are the results?

The calculators use the standard published formulas — the amortization formula for loans, the WHO weight-over-height-squared formula for BMI, and exact calendar arithmetic for ages. Results are rounded for display, so a cent or two of rounding difference against a lender's own statement is normal.

Can I use these calculators for financial or medical decisions?

Treat them as estimates. The loan calculator does not know about origination fees, insurance, or taxes, and BMI is a population-level screening measure rather than a diagnosis. Use the numbers to get oriented, then confirm with a lender or clinician.

Do they work offline and on my phone?

Yes to both. Each page is a small static document, so once it has loaded it keeps working without a connection, and every layout is built mobile-first for phones and tablets.

Which currency does the loan and tip calculator use?

None in particular. The tools work on plain numbers, so whatever currency you enter is the currency you get back. There is no exchange-rate conversion happening behind the scenes.