Free · No sign-up · Private
Free online calculators that just work.
38 accurate tools for money, health, math, home, conversions and more. Answers the moment you type, in your own currency.
Most popular
The calculators people use most
- Mortgage CalculatorMonthly payment, interest & total costFinance
- Compound Interest CalculatorGrow savings with compound growthFinance
- BMI CalculatorBody Mass Index with WHO categoryHealth
- Calorie CalculatorDaily calories for your goalHealth
- Percentage CalculatorX% of Y, % change, and moreMath
- Running Pace CalculatorPace, time, or distanceFitness
- Profit Margin CalculatorGross margin, markup & pricingBusiness
- Age CalculatorExact age in years, months & daysTax & Date
All calculators
Find the right calculator
All 38 tools in one place. Pick a category to narrow the list. Each calculator has its own page with a plain-English explanation of the formula and answers to common questions.
- Mortgage CalculatorMonthly payment, interest & total cost
- Compound Interest CalculatorGrow savings with compound growth
- Loan EMI CalculatorMonthly instalment for any loan
- Tip CalculatorSplit bills and calculate tips
- Salary to Hourly CalculatorConvert annual salary to hourly rate
- Simple Interest CalculatorInterest and total from P × r × t
- Savings CalculatorHigh-yield savings growth with APY
- Retirement CalculatorProjected nest egg and 4% rule income
- Inflation CalculatorFuture cost and purchasing power
- Discount CalculatorSale price, savings & stacked discounts
- BMI CalculatorBody Mass Index with WHO category
- Calorie CalculatorDaily calories for your goal
- Ideal Weight CalculatorHealthy weight range for your height
- Body Fat CalculatorBody fat % with the US Navy method
- BMR CalculatorCalories burned at rest
- Pregnancy Due Date CalculatorDue date from your last period
- Percentage CalculatorX% of Y, % change, and more
- Average CalculatorMean, median, mode & range
- Fraction CalculatorAdd, subtract, multiply & divide fractions
- Standard Deviation CalculatorSample & population SD and variance
- GPA CalculatorTerm and cumulative GPA on a 4.0 scale
- Grade CalculatorScore you need on the final exam
- Running Pace CalculatorPace, time, or distance
- Macro CalculatorProtein, carbs & fat targets
- Home Affordability CalculatorHow much house you can afford
- Rental Yield CalculatorGross yield, net yield & cap rate
- Square Footage CalculatorArea of rooms, plots and floors
- Profit Margin CalculatorGross margin, markup & pricing
- Break-Even CalculatorUnits and revenue to break even
- Markup CalculatorSelling price, profit & margin from markup
- ROI CalculatorReturn on investment & annualized ROI
- Age CalculatorExact age in years, months & days
- Date Difference CalculatorDays, weeks & months between dates
- Time CalculatorHours between times, add durations
- Sales Tax CalculatorAdd or remove sales tax, VAT & GST
- Length ConverterFeet, meters, inches, miles & more
- Weight ConverterPounds, kilograms, ounces & more
- Temperature ConverterCelsius, Fahrenheit & Kelvin
Guides
Understand the numbers
Plain-English guides with worked examples, linked to the calculators that do the math.
- Finance guideRenting vs Buying a Home: How to Compare the Real CostsCompare renting and buying on unrecoverable costs: interest, tax, upkeep, closing costs and lost investment growth, with a worked 7-year example.6 min read · November 8, 2026
- Finance guideAPR vs APY: What's the Difference?APR is the yearly rate on borrowing, often with fees and without compounding. APY includes compounding. See the formula and an APR to APY table.5 min read · November 8, 2026
- Finance guideDebt Avalanche vs Snowball: Which Pays Off Debt Faster?The avalanche method pays off debt with less interest; the snowball method gives quicker wins. See both compared month by month with three example debts.5 min read · November 8, 2026
- Finance guideHow to Build an Emergency Fund (and How Much You Need)How much to keep in an emergency fund, how to work out essential monthly expenses, how long saving takes, and where to keep the money.5 min read · November 8, 2026
- Finance guideReal Interest Rate: Why Inflation Matters for SavingsThe real interest rate is your return after inflation. See the exact formula, the quick approximation, worked examples and a table of real returns.5 min read · November 8, 2026
- Business guideHow to Price a Product: Cost-Plus Pricing ExplainedPrice a product with cost-plus pricing: add up your full unit cost, pick a target margin, turn it into a price, then check break-even and competitor prices.6 min read · November 8, 2026
How it works
An answer in three steps
- 1
Pick a calculator
Search by name or browse by topic. Every calculator has its own page, so you can bookmark the ones you use.
- 2
Enter your numbers
Start from sensible defaults for your country and change any field. Switch units or modes with one tap.
- 3
Get your answer instantly
Results update as you type, with a breakdown, the formula used and a worked example to check against.
Why AllToolsCalculator
Built the way you’d expect
Free, always
No paywalls, no premium tier and no sign-up. Every calculator is free to use.
Formula-accurate
Each tool uses a published, verified formula, explained on its own page.
Private by design
Calculations run in your browser. Nothing you type is sent or stored.
Your currency
Money calculators use your local currency and sensible local defaults.
About
Free calculators for everyday decisions
AllToolsCalculator is a collection of 38 free online calculators for the numbers people work out most often: loan and mortgage payments, savings growth, body mass index and daily calories, percentages and averages, home affordability, unit conversions and the number of days between two dates.
Every calculator uses a standard, published method. The mortgage and loan tools use the amortization formula lenders use, the calorie and BMR tools use the Mifflin–St Jeor equation, and BMI categories follow the World Health Organization. Each page shows its formula, a worked example and its assumptions, so you can check the answer yourself. Our methodology page lists the sources.
Money calculators show results in your local currency, with sensible starting values for 75 countries, and you can switch country at any time. All calculations run in your browser, so nothing you type is sent to our servers.
Results are estimates to help you plan. For important financial, medical or legal decisions, check with a qualified professional.
FAQ
Common questions
Are the calculators really free?
Yes. Every calculator on the site is free to use, with no account, sign-up or usage limit.
Do you store the numbers I enter?
No. Calculations run entirely in your browser, and the values you type are not sent to or stored on our servers.
How accurate are the results?
Each calculator uses a standard, published formula and is tested against worked examples. Results are estimates based on the numbers you enter, so for important decisions check them with a qualified professional.
Can I use my own currency?
Yes. Money calculators detect your country and show your local currency with typical defaults. You can pick any of 75 countries from the menu above the calculator.
Do the calculators work on phones?
Yes. Every page is designed for phones, tablets and computers, and the results update as you type on any device.
Can I suggest a new calculator?
Yes. Use the Suggest a calculator page to tell us what you need. New tools are chosen based on what people ask for.
Can’t find the calculator you need?
We add new tools every month based on what people ask for.