How to use this health & lifestyle hub
Health calculators translate body measurements into categories and targets that doctors, nutritionists and sports coaches use in their day-to-day practice. The tools in this hub do not diagnose or prescribe — they give you the same starting-point numbers a GP or personal trainer would use when talking to you.
The most-used tools here are BMI and BMR, which sit at the base of almost every health and fitness plan. BMI categorises you on a population-level scale (WHO ranges); BMR estimates the calories your body burns at rest, which is the anchor for building a daily calorie target. Layer on activity level, macro split, and water intake and you have a complete baseline for a personal plan.
Where these tools shine is in forcing specificity. "Eat healthier" is useless as a plan; "consume 2,100 kcal/day with 150g protein" is a target you can measure against. Similarly, "run more" becomes "target 5:30/km pace on easy runs and hit a Zone 3 heart rate of 140-155 bpm during intervals" once you have the pace and heart rate calculators dialled in.
Always treat results as a starting point for conversation with a qualified clinician. BMI in particular doesn't account for muscle mass — athletes often register "overweight" despite low body fat. Use the Body Fat calculator alongside for a more accurate picture. For serious health concerns, these tools are a signal to speak to a GP, not a replacement.
Most popular calculators
Start with the tools people usually need first, then move into the grouped sections below for more specific scenarios.
BMI Calculator
Calculate your Body Mass Index using height and weight to assess whether you are underweight, healthy, overweight or obese using standard BMI classifications.
BMR Calculator
Calculate your Basal Metabolic Rate to find the calories needed at rest each day. Use BMR to set a calorie target for weight loss, maintenance or muscle gain.
Calorie Calculator
Body Fat Calculator
Guides that support this category
Use these editorial guides when you need more context before choosing the right calculator.
Body composition
The core assessment tools — BMI for category, BMR for resting burn, body-fat and ideal-weight for nuance.
BMI Calculator
Calculate your Body Mass Index using height and weight to assess whether you are underweight, healthy, overweight or obese using standard BMI classifications.
BMR Calculator
Calculate your Basal Metabolic Rate to find the calories needed at rest each day. Use BMR to set a calorie target for weight loss, maintenance or muscle gain.
Body Fat Calculator
Estimate body fat percentage using waist, hip and neck measurements. Understand your body composition and track progress toward your health and fitness goals.
Ideal Weight Calculator
Calculate your ideal weight range based on height and healthy BMI. Find your target weight.
Nutrition planning
Daily calorie targets, macro splits, and hydration — the building blocks of any serious nutrition plan.
Calorie Calculator
Calculate your daily calorie needs for maintenance, weight loss, or weight gain.
Macros Split Calculator
Calculate your daily macronutrient split of protein, carbohydrates and fat based on your calorie goal. Plan your diet to support weight loss or muscle gain.
Water Intake Calculator
Calculate your recommended daily water intake based on weight and activity level.
Training and performance
For runners and gym-goers: heart-rate training zones and target running pace.