Free Online Calculators for Every Number Problem
Percentages, fractions, health, and physics calculators with clear steps shown for every answer. No sign-up, no downloads, just pick a tool and go.
General scientific calculator. Need something specific? Browse the full directory below.
Browse All Calculators
Organized by category so you can find the right tool fast. New calculators are added regularly.
🔢 Numbers & Fractions 5
🩺 Health & Body 3
Most Used Calculators
Jump straight to the tools people search for most.
Built for How You Actually Use It
Bills & Expenses
Split a dinner bill, check a rent increase against your lease cap, or work out how much of your income goes to fixed costs.
Shopping
Check whether a discount is real, compare pack sizes, or round a measurement to the nearest fraction your tape measure actually has.
Students
Check homework answers with the working shown, not just the final number, across maths, physics, and computer science topics.
Health & Fitness
Estimate BMI, maintenance calories, and see how activity level or goal pace changes your numbers, with honest limitations included.
Why All Calculator
Every step shown
Results come with the working behind them, not just a final number, so you can check the method as well as the answer.
No clutter
No sign-up walls, no pop-ups. Open a calculator and it's ready to use immediately.
Backed by real guides
Every calculator page includes a full explanation of the formulas, common mistakes, and where it comes up in real life.
From the Guides
Each calculator page includes its own in-depth guide. Here are a few places to start.
How Percentages Work
All five percentage question types explained, with worked examples and common mistakes.
Read the guide →Simplifying Fractions and Radicals
How GCF, prime factorization, and simplification connect across fractions and square roots.
Read the guide →Understanding BMI's Limitations
What BMI can and can't tell you, and who it applies to less reliably.
Read the guide →Frequently Asked Questions
What calculators are available on this site?
The site covers number and fraction calculators (percentage, fraction, decimal to fraction, square root, prime factorization), a binary calculator, health calculators (BMI, calorie, age), and a velocity calculator, with more being added regularly.
Are these calculators free to use?
Yes, every calculator on the site is free, with no subscription, trial period, or account required.
Do the calculators show how the answer was worked out?
Yes, each calculator displays the formula and working behind the result, not just the final number.
Can I use these calculators on my phone?
Yes, every calculator is built to work on mobile, tablet, and desktop without needing an app.
Will more calculators be added?
Yes, new calculators are added on an ongoing basis, particularly in categories like computer science and physics that currently have fewer tools than the numbers and health categories.