Calculators
Arithmetic that is quicker to ask than to do: how many days between two dates, what percent of what, how old somebody is on a given day. Each answers as you type, shows its working so you can check it or paste it into an email, and runs entirely in your browser — the numbers you are working with are nobody else’s business. That last part is the reason these math calculators exist separately from the ones a search engine puts at the top of the page: a salary, a loan balance or a body weight is a figure worth keeping on your own machine, and an answer box that phones home is a strange place to type one.
25 tools and counting
Pregnancy CalculatorA due date calculator that also tells you how many weeks you are todayBMI CalculatorA BMI calculator in metric or imperial, worked out in your browser.Body Fat CalculatorA body fat calculator that works from a tape measure, using the US Navy method.Calorie CalculatorWork out how many calories you burn a day, and what to eat for a goal.Pace CalculatorA running pace calculator: give any two of distance, time and pace to get the third.One Rep Max CalculatorA one rep max calculator that shows the training percentages too, not just the number.Sleep CalculatorA sleep calculator that works backwards from when you have to be up.Age CalculatorAn age calculator: your exact age in years, months and days, from a date of birth.Average CalculatorA mean median mode calculator, with standard deviation and the spread.Date DifferenceHow many days between two dates — plus weeks, months and working days.Days Until ChristmasHow many days until Christmas — counted in sleeps, not hours, and right across time zones.Fraction CalculatorA fraction calculator for adding, subtracting, multiplying and dividing — exactly.Fuel Cost CalculatorA fuel cost calculator for any drive — your units, your currency, split however you like.GPA CalculatorA GPA calculator on the 4.0 scale, weighted by the credits each course is worth.Loan CalculatorA loan calculator for the monthly payment, and how much of it is interest.Business DaysCount forward or back a number of working days and see where you land.Compound InterestA compound interest calculator with regular deposits and any compounding frequency.Percentage CalculatorA percentage increase calculator — and the other three sums people mean.Ratio CalculatorA ratio calculator: reduce to lowest terms, or find the missing number.Roman NumeralsA Roman numeral converter — numbers to numerals, and numerals back to numbers.Salary CalculatorA salary calculator that goes hourly to annual and back — the same pay written every way, before tax.Split Rent CalculatorA split rent calculator for housemates: by room size, by income or evenly, and it always adds up to the rent.Time Card CalculatorA time card calculator for hours worked, breaks and overtime across a week.Tip CalculatorWork out the tip and split the bill into amounts people can actually pay.VAT CalculatorAdd VAT to a price, or take it back out of one — the sum people get wrong.