Health calculators
Simple health calculators. They give general information and aren’t a substitute for a doctor’s advice.
6 tools
- BMI calculatorBody mass index and healthy range
- Pregnancy due date calculatorDue date and weeks pregnant
- Ovulation calculatorFertile days and next period
- Sleep calculatorBest times to sleep and wake up
- Child vaccination scheduleVisit dates from your child’s birth date
- Water intake calculatorHow much water to drink each day
About these tools
Health calculators for everyday questions: check your body mass index (BMI) against the World Health Organization ranges, estimate a pregnancy due date from the last period or conception date, and see your most fertile days and next period.
Each calculator shows how the result is worked out, and nothing you enter leaves your device. They give estimates for general information only, so talk to your doctor about your own health, a pregnancy, or anything that worries you.
Common questions
How is BMI calculated?
BMI is your weight in kilograms divided by your height in metres squared. For example, 70 kg ÷ (1.70 m × 1.70 m) = 24.2. BMI calculator
How is the due date calculated?
The usual method adds 280 days (40 weeks) to the first day of your last period, adjusted if your cycle is longer or shorter than 28 days. From a conception date, it adds 266 days. Pregnancy due date calculator
How is ovulation estimated?
Ovulation usually happens about 14 days before the next period. The calculator finds your next period from your cycle length, then counts back 14 days. Ovulation calculator
What is a sleep cycle?
Sleep moves through light, deep and dream (REM) stages in cycles of about 90 minutes. Waking at the end of a cycle usually feels easier than waking in the middle. Sleep calculator
When are babies vaccinated in Saudi Arabia?
The Ministry of Health schedule has visits at birth, 2, 4, 6, 9, 12, 18 and 24 months, then at 4–6 years before school, and at 11, 12 and 18 years. Child vaccination schedule
How much water should I drink a day?
A common guide is about 33 ml per kilogram of body weight, plus more for exercise and hot weather. A 75 kg adult needs roughly 2.5 litres before extras. Water intake calculator