Calculators

Work out percentages and the number of days between two dates.

Percentage CalculatorWork out percentages, percentage of a value and percent changes.Date Difference CalculatorFind the days, weeks and weekdays between two dates.Age CalculatorExact age in years, months and days, plus a birthday countdown.Unit ConverterConvert length, mass, temperature and data units precisely.Aspect Ratio CalculatorFind a ratio and compute the matching dimensions for a resize.Percentage Change CalculatorMeasure the percent increase or decrease between two values.Discount CalculatorFinal price after a discount — or the original price before it.Compound Interest CalculatorProject a balance with interest frequency and optional deposits.BMI CalculatorBody Mass Index with the standard WHO weight category.

About these calculators tools

Two focused calculators for questions that come up constantly: percentage maths and date differences. Both show the calculation steps so you can check the result rather than trust a black box.

Each tool is a small, focused utility with its own page, its own instructions and its own set of supported inputs. There is no account to create and no server-side processing step: the work happens on your device.