Free Health & Nutrition Calculators
50+ free calculators for calories, macros, body composition, and fitness. Instant results. No signup. No spam.
Formulas based on peer-reviewed research · Mifflin-St Jeor · US Navy · ACSM · Updated 2026
Most Popular Calculators
Calorie Calculator
Find your daily calorie needs for weight loss, maintenance, or muscle gain based on your stats and activity.
Calculate now →TDEE Calculator
Calculate Total Daily Energy Expenditure — your true maintenance calories including all activity.
Calculate now →BMI Calculator
Calculate your Body Mass Index and see which weight category you fall into.
Calculate now →Macro Calculator
Get your personalized protein, carb, and fat targets based on your calorie goal.
Calculate now →Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method.
Calculate now →Water Intake Calculator
Find out how much water you should drink daily based on your weight and activity level.
Calculate now →Browse by Category
Calories & Metabolism
BMR, TDEE, calorie needs for weight loss, gain, and maintenance.
10 tools →Macros & Nutrition
Protein, carb, and fat targets. Fiber, sodium, and micronutrient guides.
10 tools →Body Composition
BMI, body fat %, lean mass, ideal weight, and body shape analysis.
10 tools →Lifestyle Optimization
Water intake, sleep cycles, heart rate zones, and calories burned.
10 tools →Specialized Tools
Keto macros, intermittent fasting, pregnancy weight, and viral tools.
10 tools →Why Use Free Nutrition Calculator?
Whether you're tracking macros, trying to lose weight, building muscle, or just curious about your daily calorie needs, Free Nutrition Calculator gives you instant, science-backed answers without the signup walls and premium upsells found on other health sites.
Every calculator uses validated formulas from peer-reviewed research — the Mifflin-St Jeor equation for BMR, the US Navy method for body fat, and ACSM guidelines for exercise calorie expenditure. You get a low, mid, and high range where relevant, along with practical breakdown tables so you understand exactly how your number was calculated.
50 Tools, Zero Friction
From the basics (BMI, calories, macros) to specialized tools (keto macros, intermittent fasting windows, metabolic age, pregnancy weight gain), every tool works the same way: enter your numbers, hit Calculate, get your answer instantly inline. No page reloads. No popups. No required email.
Medical Disclaimer
All results are estimates for general informational purposes. These calculators do not replace the advice of a qualified healthcare provider, registered dietitian, or certified fitness professional. Always consult a professional before making significant changes to your diet or exercise routine.