One Place. Every Calculation.
Everything Calculator
40 free calculators for health, money and maths. Every result shows the formula and the working, so you can follow exactly how it was reached.
- Instant results
- Formulas shown
- No sign-up
- Always free
Popular calculators
- BMI CalculatorBody Mass Index from height and weight, with the WHO category.Calculate1
- Calorie CalculatorDaily calorie needs (TDEE) for maintaining, losing or gaining weight.Calculate2
- Compound Interest CalculatorGrowth of savings or debt when interest earns interest, with optional deposits.Calculate3
- Discount CalculatorSale price and savings from one or two stacked discounts.Calculate4
- GST / Sales Tax CalculatorAdd or remove GST, VAT or sales tax at any rate.Calculate5
- Loan CalculatorMonthly repayment, total interest and total cost for any amortising loan.Calculate6
- Mortgage CalculatorMonthly mortgage payment including tax and insurance, with total interest.Calculate7
- Payment CalculatorSolve for the payment, or for the term a fixed payment implies.Calculate8
Browse by category
- Health & FitnessEstimate body composition, daily energy requirements and training targets using the same equations used in clinical and sports-science literature. Every input is explained so you understand where the number comes from.9 calculators
- Finance & MoneyWork out repayments, interest, investment growth, take-home pay and pricing margins. Each finance tool shows the formula and the intermediate steps so you can check the maths yourself.21 calculators
- MathematicsFast, exact answers for the arithmetic and statistics problems that come up in study and work, with the working shown step by step.10 calculators
Prefer a list? See the full directory of calculators.
What is Everything Calculator?
Everything Calculator is a free collection of online calculators for health, money and maths. Each tool shows the formula it uses, the calculation step by step and a plain-English explanation of what the result means, so nothing happens in a black box.
Why use Everything Calculator?
- Free to use, with no account required
- The formula behind every result is published on the page
- Step-by-step working, not just a final number
- Works on phones, tablets and desktops
- Grouped into health, finance and maths categories
How our calculators work
Every calculator applies an established, published mathematical formula to the values you enter — nothing is estimated or guessed behind the scenes. Each page lists the formula, a worked example and the limits of what the result can tell you. Results are informational estimates, not medical or financial advice.
Popular calculator guides
Each of these pages explains the method behind the calculator as well as running it.
- How the bmi calculator worksBody Mass Index from height and weight, with the WHO category.
- How the calorie calculator worksDaily calorie needs (TDEE) for maintaining, losing or gaining weight.
- How the compound interest calculator worksGrowth of savings or debt when interest earns interest, with optional deposits.
- How the discount calculator worksSale price and savings from one or two stacked discounts.
- How the gst / sales tax calculator worksAdd or remove GST, VAT or sales tax at any rate.
- How the loan calculator worksMonthly repayment, total interest and total cost for any amortising loan.
- How the mortgage calculator worksMonthly mortgage payment including tax and insurance, with total interest.
- How the payment calculator worksSolve for the payment, or for the term a fixed payment implies.
- How the percentage calculator worksEvery common percentage question in one tool.
Frequently asked questions
- Are the calculators free to use?
- Yes. Every calculator on the site is free, works in your browser and needs no account or sign-up.
- Do I need to create an account?
- No. You can open any calculator and get a result straight away. We do not ask for an email address.
- How are the results worked out?
- Each calculator applies a published, established formula to the values you enter. The formula, the worked steps and an example are shown on every calculator page so you can check the maths yourself.
- Are the results advice?
- No. Results are informational estimates based only on the figures you enter. Health results are not a diagnosis and finance results are not financial advice — check important decisions with a qualified professional.
- Do the calculators work on a phone?
- Yes. Every page is designed to work on small screens as well as on a desktop.
- What if I find a mistake?
- Please report it through the contact page. We check reported errors and correct them.