Calculator
Age Calculator
Exact age in years, months, and days from date of birth — plus next birthday and life-stage context for health screening.
Calendar-accurate date difference
Health Tools
Calculators & metabolism 7
Calculator
BMI Calculator
Calculate Body Mass Index using WHO international weight categories. Instant underweight, normal, overweight, or obesity classification.
WHO: weight (kg) divided by height (m) squared
Calculator
Calorie Calculator
Free calorie calculator: estimate daily calories (BMR & TDEE) for weight maintenance, loss, or gain using age, sex, height, weight, and activity.
Mifflin-St Jeor BMR with activity multiplier
Calculator
BMR & TDEE Calculator
Basal metabolic rate and total daily energy expenditure using the Mifflin-St Jeor equation.
Mifflin-St Jeor BMR x activity factor
Calculator
Pregnancy Calculator
Due date, gestational age, and trimester from LMP or conception date with week-by-week timeline.
Naegele rule (LMP + 280 days)
Calculator
Ideal Weight Calculator
Healthy weight range from height and sex using the Robinson formula with plus/minus 10% band.
Robinson formula by height and sex
Calculator
Water Intake Calculator
Daily fluid intake in litres and cups from body weight and activity level.
33 ml per kg with activity adjustment
Medication & daily care 1
Reference & education 5
Reference
Lab Result Guide
Compare a lab value to common reference intervals. Always follow the range on your own report.
Common lab reference intervals
Reference
Child Growth Percentiles
WHO weight-for-age percentile estimate for children 24–60 months.
Simplified WHO growth curves
Reference
Common Symptoms
Browse symptoms by body area with plain-language explanations and when to seek urgent care.
Curated symptom library with body map
Reference
Common Diseases & Conditions
Search conditions with overview, typical symptoms, and links to find specialists.
Indexed condition articles
Reference
Medical Glossary
Look up medical terms, abbreviations, and definitions from reports and prescriptions.
Searchable A-Z terminology
Wellness & travel 3
Wellness
Weather & Air Quality
Temperature, humidity, UV index, and air quality for any city — asthma, allergies, and travel planning.
Open-Meteo weather and AQI
Travel
Currency Converter
Convert medical travel costs between currencies for international care planning.
Live exchange rate lookup
Travel
Flight Search
Search flights for medical tourism and cross-border healthcare travel.
Flight search integration
Frequently asked questions
Are DoctorBookly health tools free?
Yes. All calculators and reference tools are free in your browser. No account is required for most tools.
Can these tools diagnose a medical condition?
No. They are for general education only. Always consult a licensed doctor, nurse, or pharmacist for diagnosis and treatment.
Which formula does the BMI calculator use?
Our BMI calculator uses the WHO standard: BMI equals weight in kilograms divided by height in metres squared.
Do tools open on their own page?
Yes. Each card opens a dedicated tool page with full calculator or reference content — not an on-page section.