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Everyday & Health

Dates, units, BMI and the small math of daily life. 20 free tools, each one showing the math behind its answer and running entirely in your browser.

Everyday pages cover the small arithmetic of a life: dates, ages and working days; unit and time-zone conversion; BMI and body fat; calories, macros and a target weight; sleep timing; hydration; running pace; GPA; and splitting a bill between people.

Where two conventions disagree, both are printed instead of one being chosen silently: WHO and Asia-Pacific BMI cut-offs, Mifflin-St Jeor and Harris-Benedict, metric and imperial rounding on a converted unit.

Refusal is part of the design here. A calorie floor that would be unsafe to aim for, or an input that would imply a negative quantity, is named as a limit rather than returned as a number.

All 20 Everyday & Health tools

Age CalculatorWork out an exact age in years, months and days, plus days alive, the weekday you were born on and a countdown to the next birthday.Calculate your age →
BMI CalculatorWork out BMI in metric or imperial units, see both the WHO and Asia-Pacific categories, the healthy weight band for your height, and what other weights read as.Calculate your BMI →
BMR CalculatorEstimate your basal metabolic rate from the Mifflin-St Jeor and Harris-Benedict equations, see the resting burn per hour, and test a five-unit change.Estimate your resting burn →
Body Fat CalculatorEstimate your body fat percentage from neck, waist and hip measurements with the US Navy method, the error band around the number, and how to read the bands.Estimate your body fat percentage →
Calorie CalculatorEstimate maintenance calories from two published equations, set a deficit or surplus for a target rate of weight change, and split the result into macros.Estimate daily calories →
Currency ConverterConvert an amount at the rate you were offered, and see what the markup and the fees cost against the mid-market rate, plus what other providers would pay.Convert currency →
Date CalculatorCount the days between two dates, add or subtract days, weeks, months or years, and see the weekdays, weekend days and calendar span beside the total.Add or subtract dates →
Final Grade CalculatorFind the score you need on the final exam for a target grade - including the cases where it is already secured, out of reach, or changes nothing.Find the score you need on the final →
GPA CalculatorWork out a credit-weighted GPA, see it weighted and unweighted, find the score your final exam needs, and combine a new term with your cumulative average.Calculate your GPA →
Heart Rate Zones CalculatorEnter your age and resting heart rate for five training zones built on two max-heart-rate estimates. See why the ranges are honest, not promises.Find your training zones →
Ideal Weight CalculatorSee what the Devine, Hamwi, Robinson and Miller formulas each give, plus the WHO and Asia-Pacific healthy weight bands for your own height.Find an ideal body weight range →
Macro CalculatorTurn a calorie number you already have into grams of protein, carbohydrate and fat, at four common splits or your own percentages, with a per-meal view.Split calories into macros →
Percentage CalculatorWork out a percentage of an amount, an amount as a percentage, percentage change and percentage points, and convert decimals, fractions and scientific notation.Calculate percentages →
Pregnancy Due Date CalculatorWork out a pregnancy due date from the last period, a dating scan or an IVF transfer, with the antenatal milestones and how far along you are today.Estimate a due date →
Running Pace CalculatorWork out your running pace from a distance and time: per kilometer and per mile, as speed, and projected across 5k, 10k, half marathon and marathon.Work out your running pace →
Sleep CalculatorFind bedtimes that end a full sleep cycle, or wake times for the bedtime you choose. See cycle-length caveats and why timing is a target, not a promise.Time your sleep to a cycle →
Time Zone ConverterConvert a date and time between time zones, with offsets, daylight saving, the local date on each side and the clock changes behind the numbers.Convert time zones →
Tip CalculatorWork out a tip on the pre-tax subtotal or the taxed total, split the bill so the cents add up, stack discounts properly, and see margin beside markup.Calculate a tip →
Unit ConverterConvert miles, kilograms, gallons, Celsius and more: the exact factor is printed beside the answer and every unit of the category appears in one table.Convert units →
Water Intake CalculatorEstimate your daily water target with a weight-based range and official guidance. See what comes from food, how sweat changes it, and when to follow thirst.Estimate how much to drink →

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