Your complete resource for health and fitness calculations. All calculators are aligned with NHS guidelines and use evidence-based formulas. Track your BMI, calculate calorie needs, plan your macros, and monitor your fitness progress with our free, accurate tools.
Calculate your BMI, ideal weight, body fat percentage and other key metrics. These tools help you understand your current health status and set realistic goals.
Calculate your Body Mass Index with NHS category classification and healthy weight range.
NHS GuidelinesFind your ideal weight range based on height, gender, and body frame size.
Multiple FormulasEstimate body fat percentage using measurements. More accurate than BMI for fitness tracking.
FitnessCalculate WHR to assess health risks associated with body fat distribution.
Health RiskBody Mass Index (BMI) is calculated as weight (kg) divided by height squared (m²). The NHS uses these categories:
| BMI Range | Category | Health Risk |
|---|---|---|
| Under 18.5 | Underweight | Increased risk of nutritional deficiency |
| 18.5 - 24.9 | Healthy Weight | Lower risk of weight-related conditions |
| 25 - 29.9 | Overweight | Increased risk of heart disease, diabetes |
| 30 - 34.9 | Obese Class I | High risk of weight-related conditions |
| 35 - 39.9 | Obese Class II | Very high risk |
| 40+ | Obese Class III | Extremely high risk |
Note: BMI doesn't distinguish between muscle and fat. Athletes with high muscle mass may have elevated BMI while being healthy.
Plan your nutrition with our calorie and macro calculators. Whether you want to lose weight, gain muscle, or maintain your current physique, these tools provide personalized targets.
Calculate daily calorie needs based on age, weight, height, and activity level.
Weight ManagementCalculate Total Daily Energy Expenditure using the Mifflin-St Jeor equation.
Science-BasedGet personalized protein, carb, and fat targets for your goals.
Custom RatiosCalculate the calorie deficit needed to reach your weight loss goal.
Weight LossCalculate daily protein needs based on your goals and activity level.
Muscle BuildingCalculate your Basal Metabolic Rate - calories burned at complete rest.
MetabolismOptimize your workouts with heart rate zones, running pace calculators, and exercise tracking tools.
Calculate training zones for fat burning, cardio, and peak performance.
TrainingCalculate pace, time, or distance for running and walking activities.
RunningConvert step count to distance based on your stride length.
WalkingSpecialized calculators for pregnancy, fertility, and women's health tracking.
Calculate your estimated due date and pregnancy timeline.
PregnancyPredict fertile days and ovulation based on your cycle.
FertilityTrack and predict your menstrual cycle.
Cycle TrackingAccording to NHS guidelines, a healthy BMI is between 18.5 and 24.9. A BMI under 18.5 is classified as underweight, 25-29.9 as overweight, and 30+ as obese. However, BMI may not be accurate for athletes with high muscle mass, elderly people, or certain ethnic groups. For a more complete picture, consider also measuring waist circumference and body fat percentage.
NHS guidelines suggest approximately 2,000 calories per day for women and 2,500 for men to maintain a healthy weight. However, your actual needs depend on your age, height, weight, and activity level. Use our TDEE calculator for a personalized estimate. For weight loss, a deficit of 500-750 calories per day typically results in 0.5-1kg loss per week.
A balanced diet typically includes 45-65% carbohydrates, 20-35% fats, and 10-35% protein according to NHS guidelines. For weight loss, higher protein intake (25-30%) can help preserve muscle mass. Athletes and those building muscle may need 1.6-2.2g protein per kg of body weight. Use our macro calculator to get personalized targets.