Nutri Free Health & Wellness Calculators
Science-backed tools to help you understand your body, optimize your health, and make informed decisions about your wellness journey. All calculators are free, instant, and require no sign-up.
Sleep Cycle Calculator
Find your ideal bedtime or wake time based on 90-minute sleep cycles.
Calorie Calculator
Calculate daily calorie needs for weight loss, maintenance, or muscle gain.
BMI Calculator
Calculate your Body Mass Index with health insights for women and men.
BMR Calculator
Find your Basal Metabolic Rate to understand calories burned at rest.
Body Fat % Calculator
Estimate body fat percentage using the US Navy method. No calipers needed.
Weight Loss Calculator
Calculate how long it will take to reach your goal weight safely.
Ideal Body Weight Calculator
Find your ideal weight range using four validated medical formulas.
HbA1c Calculator
Convert HbA1c to average blood sugar and understand your results.
FFMI Calculator
Measure muscle development relative to height with Fat-Free Mass Index.
LDL Cholesterol Calculator
Calculate LDL cholesterol from your lipid panel using the Friedewald equation.
Heart Rate Zone Calculator
Find your five training heart rate zones for optimal workout intensity.
WHR Calculator
Calculate your Waist-to-Hip Ratio to assess abdominal fat and health risk.
Vitamin D Calculator
Estimate your daily Vitamin D needs based on age, sun exposure, and lifestyle.
Why Use Our Health Calculators?
Understanding your body is the first step toward better health. Our collection of 13 free health and wellness calculators gives you instant, personalized insights based on validated scientific formulas used by healthcare professionals worldwide.
Every calculator on this page uses peer-reviewed equations and established medical guidelines. The BMR and Calorie calculators use the Mifflin-St Jeor equation, preferred by the American Dietetic Association. The Body Fat calculator uses the US Navy method. The HbA1c calculator uses the ADAG study formula. The LDL calculator uses the Friedewald equation.
All calculations happen instantly in your browser. We do not store your health data, require an account, or charge any fees. These tools are designed to educate and empower you to have more informed conversations with your healthcare providers.
The Sleep-Cortisol-Weight Connection
As you explore these calculators, you will notice a recurring theme: sleep quality affects nearly every health metric. Research consistently shows that poor sleep increases cortisol (the stress hormone), which raises BMI, reduces BMR, increases body fat storage, disrupts blood sugar regulation, and impairs cardiovascular health.
At Nutri Boost Lifestyle, we believe that fixing sleep is the highest-leverage health intervention most people overlook. Our natural Sleep Patches, Magnesium Bisglycinate, and Ashwagandha Gummies are designed to address the root causes of poor sleep and high cortisol, not just mask the symptoms.