Kalkulatora.net — free online calculators that show their work
Kalkulatora.net is a library of more than 300 free calculators, each one localized for 21 countries and written in the language people there actually speak. Every tool shows the formula it uses, walks through a worked example with real numbers, and answers the questions people usually ask next — so you can check the maths yourself instead of trusting a black box.
There is nothing to install and nothing to sign up for. Type your numbers in, get the result, and read the short guide underneath when you want to understand where the figure came from or what to watch out for.
Popular calculators
- Mortgage CalculatorWork out monthly payments, total interest and amortization before you talk to a bank.
- BMI CalculatorCheck your body mass index and see which WHO category your result falls into.
- Percentage CalculatorPercentages of numbers, percentage change, discounts and markups in one place.
- VAT CalculatorAdd or remove VAT from a price at standard and reduced rates.
- Auto Loan CalculatorEstimate the monthly payment and total cost of financing a car.
- Calorie CalculatorDaily calorie needs based on your age, body and activity level.
- Compound Interest CalculatorSee how savings grow when interest compounds month after month.
- Salary CalculatorConvert between gross and net pay and hourly, monthly and annual rates.
- Age CalculatorExact age in years, months and days between two dates.
- Currency ConverterConvert between major world currencies with clear, readable results.
- Date Difference CalculatorCount days, weeks and months between any two dates.
- Loan Payment CalculatorPayment, interest and payoff schedule for any personal loan.
Browse by category
- FinanceLoans, interest, savings, salary and investment maths.
- HealthBMI, calories, body fat, pregnancy and fitness metrics.
- TaxesVAT, income tax and take-home pay for your country.
- ConversionUnits of length, weight, volume, temperature and more.
- ConstructionConcrete, bricks, paint, tiles and material estimates.
- MathPercentages, fractions, statistics and everyday arithmetic.
- Date & TimeAge, date differences, working days and countdowns.
- AutomotiveFuel consumption, trip costs and vehicle finance.
- LifestyleCooking, gardening, pets and day-to-day helpers.
- EngineeringElectrical, mechanical and manufacturing calculators.
Choose your country and language
Each edition uses the local language, currency, tax rules and measurement conventions, and is indexed separately for its country. Pick yours — the site will remember the choice on your next visit.
- България
- United States
- United Kingdom
- Canada
- Australia
- Singapore
- Ireland
- New Zealand
- India
- South Africa
- Deutschland
- Österreich
- Schweiz
- România
- Moldova
- Ελλάδα
- Κύπρος
- Србија
- Bosna
- Crna Gora
- Македонија
Why people use it
Most calculator sites give you a number and leave you guessing. Here the calculation is only half of the page: the other half explains the formula, shows a worked example step by step, lists the mistakes that most often distort the result, and points you to related tools when the question you actually have is slightly different from the one you typed into a search engine.
The site is free, runs entirely in your browser, and does not send the figures you enter anywhere. Whether you are comparing mortgage offers, converting units for a recipe, or checking what a salary means after tax, the answer is a few keystrokes away.