Calculators and timers
5 toolsWork out ages, BMI, time zones and Hijri dates, or run a countdown timer.
- Age CalculatorHow old you are to the day, on today's date or any other, with your next birthday counted down.
- BMI CalculatorBody mass index for adults in metric or imperial units, with the WHO category and the weight range it implies.
- Countdown TimerTime a task for minutes or count down to an exam, launch or holiday, with an alert at zero and a link to share.
- Time Zone ConverterPick a time in one place and see it everywhere else, with daylight saving worked out for the exact date.
- Hijri Date ConverterGregorian to Hijri and back with the Umm al-Qura calendar, shown in English and Arabic.
How these tools work
These calculators answer everyday questions about dates, time and health that are easy to get wrong in your head. They run entirely in your browser: what you type, such as a birth date, a height or a weight, is calculated on your device and is not sent anywhere or kept after you leave the page.
Age Calculator gives your exact age in years, months and days on today's date or any other, with the total weeks and days lived and a countdown to your next birthday. BMI Calculator works in metric or imperial units and shows the WHO category and the healthy weight range for your height. Time Zone Converter takes a time in one place and shows it everywhere else, with daylight saving applied for that exact date. Hijri Date Converter switches between Gregorian and Hijri dates using the Umm al-Qura calendar, in English and Arabic. Countdown Timer times a task or counts down to a date, with a sound and a notification at zero and a link you can share.
Dates and times follow your device's clock and time zone, so results match the calendar on your phone or computer.
Frequently asked questions
Is my birth date or weight saved?
No. The calculations run in your browser and nothing is sent to a server or kept after you close the page. Countdown Timer puts its target in a link only when you choose to share it.
Which Hijri calendar is used?
The Umm al-Qura calendar, the official calendar of Saudi Arabia. Dates of religious occasions can differ by a day in countries that rely on local moon sighting.
Is BMI accurate for everyone?
BMI is a screening measure for adults. It does not tell muscle from fat and does not apply to children or pregnancy, so treat the result as a starting point for a conversation with a doctor rather than a diagnosis.
Does the time zone converter handle daylight saving?
Yes. It applies the daylight saving rules in force on the date you pick and flags when the converted time falls on the previous or the next day.