What these tools are for
Calculators do the small sums and conversions that come up at school, at work and around the house. The Roman numeral converter turns a number from 1 to 3,999 into Roman numerals, or reads a numeral back as a number, and breaks it down by thousands, hundreds, tens and units so you can see how it’s built. The mean, median, mode calculator takes a list you type or paste, even a column from a spreadsheet, and gives its average, middle and most common values with the sum, minimum, maximum and range. The BMI calculator divides your weight by the square of your height, in metric or imperial units, and names the WHO adult band the result falls in. The age calculator gives an exact age on any date in years, months and days, with the next birthday. The due date calculator applies Naegele’s rule to the first day of the last period, adjusted for the cycle length, and counts the weeks to a date you choose. The calorie calculator applies the Mifflin–St Jeor equation to your height, weight, age and sex for your BMR and TDEE, and takes a deficit you choose off the TDEE, in kcal and kJ.
How they work
Everything is worked out by your browser, on your device. Nothing is uploaded, and there’s no account or sign-up. Open a calculator and it starts with an example already worked out; change the input and the answer follows.
Tips
- Every calculator shows how it got its answer, and Copy result puts the answer on your clipboard.
- Roman numerals are read in standard form only, so 4 is IV, not IIII. Lower case and spaces around the numeral are fine.
- In a list of numbers a comma always separates values, so write 1000, not 1,000.
- The BMI calculator keeps your choice of units, never your height or weight. The calorie calculator keeps your units, activity level and deficit, never your height, weight, sex or age.
- The age and due date calculators keep nothing you enter: after a reload the dates start again from their example values and today.