Free health and fitness calculator hub: BMI, BMR, TDEE, body fat, ideal weight, lean body mass and daily water in one place, plus links to every health tool.
Get a complete picture of your health metrics in one place. Enter your basic information to calculate BMI, BMR, TDEE, body fat percentage, ideal weight, lean body mass and a base daily water estimate. All results update instantly as you adjust your inputs. This hub also links every health and fitness tool on the site — calorie and macro calculators, running and heart-rate tools, sleep, pregnancy and pet age — grouped below so you can jump straight to the calculator you need.
DEXA scans, hydrostatic weighing, and BodPod are the most accurate methods. The US Navy circumference method used here provides a reasonable estimate within 3-4% of these lab methods.
We use the Mifflin-St Jeor equation, which is considered the most accurate for the general population. For men: 10xweight(kg) + 6.25xheight(cm) - 5xage(y) + 5. For women: 10xweight + 6.25xheight - 5xage - 161.
A BMI between 18.5 and 24.9 is considered healthy. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese. BMI is a screening tool - it doesn't account for muscle mass or body composition.
BMR (basal metabolic rate) is the calories your body needs at complete rest — about 60-75% of your daily energy needs. TDEE (total daily energy expenditure) adds your daily activity and exercise on top of BMR, so it is the number to use as your maintenance calories for weight management.
Ideal weight is estimated from height using standard formulas such as Devine, Robinson, and Miller. These give a quick reference range, but they do not account for muscle mass or frame size — your BMI, body fat percentage, and how you feel are better overall indicators.
They provide estimates based on widely used formulas (Mifflin-St Jeor, US Navy, Devine), accurate enough for general planning but not medical measurements. For personalized advice — especially with existing conditions — consult a healthcare professional.