Evidence-based tools to help you understand your body composition, set realistic goals, and track your progress.
Your go-to resource for body fat, calorie needs, and weight management calculations.
Calculate your body fat percentage using various methods including Navy, skinfold, and BMI.
Calculate calories burned during physical activities and estimate weight loss timeline.
Discover how long it will take to reach your goal weight with different calorie deficits.
Plan your weight loss with a target date and get daily calorie and macro recommendations.
Find the optimal calorie intake for maximum fat loss while preserving muscle mass.
Calculate your Total Daily Energy Expenditure to maintain your current weight.
Calculate your A Body Shape Index to assess health risk based on body shape.
Calculate Body Mass Index for adults and children with age-appropriate interpretations.
Estimate your ideal weight range using widely used clinical formulas.
Calculate personalized training zones using max heart rate or Karvonen method.
Estimate daily hydration needs based on weight and activity level.
Find optimal bedtimes or wake times based on 90-minute sleep cycles.
Check your blood pressure category from systolic and diastolic values.
Calculate your basal metabolic rate and calories at rest.
Estimate cardiovascular fitness using the Rockport 1-mile walk test.
Calculate pace per mile or kilometer plus average speed.
Estimate pregnancy due date based on key dates.
Estimate ovulation date and fertile window.
Calculate your Waist-to-Hip Ratio to assess fat distribution and health risk.
Convert between different units of measurement for weight, length, and volume.
Evidence-based articles to help you understand health, fitness, and nutrition.
Discover the truth behind common misconceptions about calorie deficits and weight loss.
February 25, 2025 • 8 min read
Energy ExpenditureUnderstand the components of TDEE and why it's crucial for weight management.
February 20, 2025 • 10 min read
Measurement MethodsCompare accuracy and practicality of various body fat assessment techniques.
February 15, 2025 • 12 min read
HealthCheck provides evidence-based calculators to help you understand your body composition, calorie needs, and set realistic fitness goals. Our tools use scientifically validated formulas and provide educational content to help you make informed decisions about your health.
Whether you're looking to lose weight, gain muscle, or simply understand your body better, our calculators offer personalized insights based on your unique measurements and goals.
While it's commonly stated that a 3,500 calorie deficit equals one pound of fat loss, the reality is more complex. Your body adapts to calorie restriction over time, and weight loss isn't linear. Our calculators use advanced models that account for these adaptations.
Research shows that factors like metabolic adaptation, hormone fluctuations, and individual genetics all affect how your body processes a calorie deficit. This is why some people may see rapid initial weight loss followed by a plateau, even while maintaining the same caloric intake.
You can't target fat loss from specific areas through exercise. Fat reduction occurs throughout the body based on genetics, hormones, and overall calorie deficit. Focus on total body fat percentage rather than "problem areas."
When your body mobilizes fat stores for energy, it does so from all adipose tissue sites simultaneously, though the proportion may differ based on your genetic predisposition. This explains why some people may notice fat loss in certain areas before others, despite performing exercises that target different muscle groups.
Extreme calorie restriction can lead to muscle loss, metabolic adaptation, and eventual weight regain. Our calculators promote sustainable approaches that preserve muscle mass and metabolic health.
Studies have consistently shown that rapid weight loss through severe caloric restriction often results in a higher percentage of lean muscle loss compared to more moderate approaches. Additionally, the body responds to extreme restriction by lowering basal metabolic rate—a protective mechanism that makes maintaining weight loss even more challenging once normal eating patterns resume.
At HealthCheck, we believe in evidence-based approaches to health and fitness. Our calculators incorporate peer-reviewed scientific research and validated formulas to provide you with accurate information about your body composition and energy needs.
For example, our Body Fat Calculator uses multiple methods including the Navy formula, which has been validated against gold standard DEXA scans. Our TDEE Calculator considers not only your basic metrics but also factors in the Thermic Effect of Food (TEF) and Non-Exercise Activity Thermogenesis (NEAT) for more precise estimations.
We regularly review emerging research in nutrition and exercise science to ensure our calculators reflect the most current understanding of human physiology. While these tools provide excellent estimates, remember that individual variations exist, and results should be used as guidance rather than absolute values.
Sustainable weight management goes beyond simple calorie counting. It involves understanding your body's unique needs, setting realistic goals, and developing consistent habits that support your long-term health.
Protein intake plays a crucial role in preserving lean muscle mass during weight loss. Research suggests that consuming between 1.6-2.2g of protein per kilogram of body weight helps maintain muscle while in a calorie deficit. Our calculators factor this research into their recommendations.
Adequate hydration is another often overlooked aspect of weight management. Proper fluid intake supports metabolic processes, helps regulate hunger signals, and enhances physical performance. A general guideline is to consume 30-40ml of water per kilogram of body weight daily, adjusted for activity level and climate.
Remember that weight fluctuations due to water retention, hormonal changes, and glycogen storage are normal and don't necessarily reflect changes in body fat. Focus on longer-term trends rather than daily fluctuations for a more accurate picture of your progress.