Health Calculators
Track your body metrics, plan your nutrition, or understand your fitness levels with calculators built on medically-recognised formulas. From BMI and body fat to calorie needs and pregnancy timelines, each tool explains exactly how the calculation works and what your results mean. These calculators are for informational purposes — always consult a healthcare professional for medical decisions.
Most popular
Calculate your Body Mass Index (BMI) to check whether you are at a healthy weigh...
Calorie CalculatorEstimate your daily calorie needs in kilocalories using the NHS-preferred Miffli...
Ideal Weight CalculatorFind your ideal weight range based on height and gender using multiple establish...
BMI Calculator
Calculate your Body Mass Index (BMI) to check whether you are at a healthy weight for your height, with NHS categories and ethnicity-adjusted thresholds.
Calorie Calculator
Estimate your daily calorie needs in kilocalories using the NHS-preferred Mifflin-St Jeor equation. Built for UK adults using NHS Eatwell Guide reference figures and BDA-aligned deficit recommendations.
Ideal Weight Calculator
Find your ideal weight range based on height and gender using multiple established formulas.
Pregnancy Due Date Calculator
Calculate your estimated due date (EDD) and map every NHS antenatal milestone — booking visit, dating scan, anomaly scan, MATB1, statutory maternity pay — week by week.
Body Fat Calculator
Estimate your body fat percentage using the US Navy method based on body measurements.
Macro Calculator
Calculate your optimal daily macronutrient intake — protein, carbohydrates, and fat — based on your goals.
Water Intake Calculator
Calculate your recommended daily water intake based on your body weight, activity level, and climate.
Heart Rate Zone Calculator
Calculate your target heart rate training zones using the Karvonen formula for more effective workouts.
Sleep Calculator
Calculate the best times to fall asleep or wake up based on 90-minute sleep cycles for more refreshing rest.
BAC Calculator
Estimate your blood alcohol content (BAC) based on drinks consumed, body weight, gender, and time elapsed.
Ovulation Calculator
Estimate your ovulation date and fertile window based on your menstrual cycle length and last period date.
Calories Burned Calculator
Calculate calories burned during exercise and daily activities using MET (Metabolic Equivalent of Task) values.
Frequently Asked Questions
Are health calculators a substitute for medical advice?
No. These tools provide estimates based on standard formulas (Mifflin-St Jeor, Karvonen, US Navy method). They're useful for tracking and planning, but consult your GP or a registered dietitian for personalised medical guidance.
Which calorie calculator should I use?
Use the Calorie Calculator for a quick daily target. Use the TDEE Calculator for a more detailed breakdown including activity levels. Use the Macro Calculator if you want protein, carbs, and fat splits.
How accurate is the BMI calculator?
BMI is a useful screening tool but doesn't account for muscle mass, bone density, or body composition. For a fuller picture, combine it with our Body Fat Calculator and Ideal Weight Calculator.
What Can You Calculate?
The BMI Calculator calculate your Body Mass Index (BMI) to check whether you are at a healthy weight for your height, with NHS categories and ethnicity-adjusted thresholds.
The Calorie Calculator estimate your daily calorie needs in kilocalories using the NHS-preferred Mifflin-St Jeor equation. Built for UK adults using NHS Eatwell Guide reference figures and BDA-aligned deficit recommendations.
The Ideal Weight Calculator find your ideal weight range based on height and gender using multiple established formulas.
The Pregnancy Due Date Calculator calculate your estimated due date (EDD) and map every NHS antenatal milestone — booking visit, dating scan, anomaly scan, MATB1, statutory maternity pay — week by week.
The Body Fat Calculator estimate your body fat percentage using the US Navy method based on body measurements.
The Macro Calculator calculate your optimal daily macronutrient intake — protein, carbohydrates, and fat — based on your goals.
The Water Intake Calculator calculate your recommended daily water intake based on your body weight, activity level, and climate.
The Heart Rate Zone Calculator calculate your target heart rate training zones using the Karvonen formula for more effective workouts.
The Sleep Calculator calculate the best times to fall asleep or wake up based on 90-minute sleep cycles for more refreshing rest.
The BAC Calculator estimate your blood alcohol content (BAC) based on drinks consumed, body weight, gender, and time elapsed.
The Ovulation Calculator estimate your ovulation date and fertile window based on your menstrual cycle length and last period date.
The Calories Burned Calculator calculate calories burned during exercise and daily activities using MET (Metabolic Equivalent of Task) values.
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