Free Calculators Library for Everyday Decisions.
Free online calculators for money, health, maths, home projects and everyday questions. Every result comes with the formula and a worked example, so you can check the number yourself, not just trust it.
Try one right now
No clicking through. Just calculate.
Every SteadyCalculator works like this one: type your numbers, get the answer and the working instantly. This is the mini version of our Percentage Calculator, the most useful small tool on the site.
Browse by category
Every calculator, in its place
Categories covering the numbers of everyday life, from a mortgage payment to a dog’s dinner. Pick a category and find your tool.
Money & Finance
Loans, mortgages, interest, tax and pay, worked out to the cent.
View calculators →Math
Percentages, fractions, exponents and the rest, step by step.
View calculators →Health & Fitness
TDEE, body fat, BMI-style measures and training numbers.
View calculators →Home & Construction
Concrete, paint, roofing, decking and garden quantities.
View calculators →Cost Estimators
What a job or service should cost before you get quotes.
View calculators →Business
Margins, commissions, valuation and business metrics.
View calculators →Engineering
Loads, forces, flow and electrical calculations.
View calculators →Science
Physics, chemistry and biology calculations, formulas included.
View calculators →Clinical Reference
Clinical scores and clearances, method stated on every page.
View calculators →Sports & Travel
Pace, handicaps, fuel costs and game statistics.
View calculators →Computing
Subnets, storage, download times and developer tools.
View calculators →Everyday & Time
Age, dates, work hours and time conversions.
View calculators →Education
GPA, grades, class rank and study budgets.
View calculators →Crafts & Everyday
Sewing, candle making, framing and sizing.
View calculators →Culture & Recreation
Calendars, charts and compatibility calculators.
View calculators →Food & Cooking
Recipe scaling, dough, brines and cooking times.
View calculators →Pet Calculators
Pet age, food, aquariums and gestation.
View calculators →Most popular
The calculators everyone reaches for
Ranked by how many people search for them every month. If you are not sure where to start, start here.
Why SteadyCalculator
A number you can check beats a number you must trust
Most calculator sites hand you an answer and ask you to believe it. Every page here shows its method.
Formulas shown
Every calculator explains the maths behind the result, in plain words, on the same page.
Worked examples
A real example with real numbers on every page, so you can follow the method end to end.
Free, no sign-up
No accounts, no email walls, no paywalled results. Open the page and calculate.
Checked data
Where a calculator depends on a rate or a method, it is verified against named sources, and the page says which.
How it works
Three steps, no friction
Pick your calculator
Search at the top, or browse the categories until the right tool turns up.
Enter your numbers
Every input is labelled in plain words, with the units shown, so there is nothing to guess.
See the answer and the working
The result, the formula used, and an example you can follow with your own numbers.
Questions
Frequently asked questions
Are these calculators free?
Yes, all of them, with no sign-up. Open any calculator and use it as often as you like.
How accurate are the results?
Each page states its formula and its sources; where a figure depends on a rate or a method, the page says so. Results are estimates for planning, not professional advice.
Do you store what I enter?
No. Calculations run in your browser; what you type is not sent to us or stored anywhere.
Why show the formula?
Because a number you cannot check is a number you should not trust. Showing the working is the whole point of this site.
Steady numbers, worked out properly.
Pick a calculator and start. Your first answer is about ten seconds away, and the working comes with it.
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