Every calculator you need, in one place.

BMI, age, percentage, loans, GPA and dozens more — free online tools that give instant answers. No sign-up, no downloads.

36+Free tools
6Categories
0Sign-up needed
InstantResults

Try one right now

These four actually work — type and see the answer instantly

Your BMI
22.9
Healthy weight range
Under 18.518.5–24.925–3030+
Your age
—
—
Result
30
20% of 150 is 30
Monthly EMI
—
—

All calculators & tools

Filter by category or search above

No calculator matches that search. Try “BMI”, “loan” or “age”.

Why people use PrimesDaily tools

Instant answers

Results update as you type. No page reloads, no waiting, no clutter between you and the answer.

Works on any phone

Every tool is built mobile-first, so it looks and works the same on a small phone screen as on a laptop.

Private by design

Calculations run in your browser. The numbers you type are never sent anywhere or stored.

Free, forever

No accounts, no paywalls, no “premium” lock on basic math. Open a tool and use it.

New tools added every week

We are building the largest free calculator library on one site — health, money, study, dates and conversions.

See all tools