Health & Fitness Calculators
Free health calculators for BMI, calories, macros, body fat percentage, heart rate zones, and protein intake. Track your fitness goals with instant, private results.
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BMI Calculator
Calculate your Body Mass Index with visual BMI scale
Use tool →Body Fat Calculator
Estimate body fat percentage using the US Navy method and BMI formula
Use tool →Calorie Calculator
Calculate daily calories (TDEE/BMR) with macro breakdowns for your goals
Use tool →Calories Burned Calculator
Calculate calories burned across 95+ activities organized in 9 categories using MET values, with heart rate zone estimation and weekly planning
Use tool →Heart Rate Zone Calculator
Calculate your target heart rate zones for optimal training using the Karvonen formula
Use tool →Macro Calculator
Calculate daily protein, carbs, and fat needs for your fitness goal
Use tool →Protein Calculator
Calculate your optimal daily protein intake based on weight, activity level, and fitness goals
Use tool →TDEE Calculator
Calculate your Total Daily Energy Expenditure based on BMR, activity level, and body composition
Use tool →Frequently Asked Questions
What health calculators are available?▾
NexTool offers free health and fitness calculators including BMI, TDEE and calorie needs, macro nutrient breakdown, body fat percentage, target heart rate zones, protein intake estimator, and more.
How accurate are the health calculators?▾
Our health calculators use widely accepted formulas (Harris-Benedict, Mifflin-St Jeor, Katch-McArdle) that are trusted by fitness professionals. They provide reliable estimates, though individual needs may vary.
Is my health data kept private?▾
Absolutely. All health calculations run entirely in your browser. No personal health information is ever transmitted to our servers or stored anywhere. Your data disappears when you close the tab.
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