Free · no sign-up

Free Online Calculators

Calculate BMI, percentages, unit conversions, age, discounts and loan payments, or generate an invoice — quick, accurate, no sign-up.

Calculate your Body Mass Index from height and weight.

X% of Y, what % one number is of another, and percentage change.

Convert length, weight, temperature and volume between units.

Calculate exact age in years, months and days.

Calculate the sale price and savings from a discount percentage.

Calculate monthly payments for a fixed-rate loan.

Fill a form with sender, client and line items, then download a clean PDF.

25-minute focus blocks with short and long breaks, sound and desktop notifications.

Convert a date and time between time zones and compare it across several cities at once.

Frequently asked questions

Are the calculators tools free?

Yes — every tool in this category is free to use, with no sign-up and no usage limits.

Do I need to install anything?

No. Everything runs in your browser (or through our server for the tools that need one) — no downloads, no extensions, no account.

Is my data kept after I use a tool?

No. Files and inputs are processed to produce your result and are not stored afterward.