Health & Fitness Calculators 💪

36 free health calculators covering body composition, nutrition, fitness performance, women's health, mental health screening, and baby & child tools. All results are for informational purposes — always consult a qualified healthcare provider for medical decisions.

36 Calculators

⚕️ These calculators provide general health information only and are not a substitute for professional medical advice, diagnosis, or treatment. If you have health concerns, please speak with a qualified healthcare provider.

Body Composition

10 tools

BMI Calculator—Body Mass Index for adults in US or metric units — healthy weight range and visual gauge→ Body Fat Calculator—Body fat percentage using the US Navy method — just a tape measure needed→ Lean Body Mass Calculator—LBM and fat mass using 4 formulas — body composition chart and protein target→ Ideal Weight Calculator—Ideal body weight for your height using Hamwi, Devine, Robinson, and Miller formulas→ Waist-to-Hip Ratio Calculator—WHR and cardiovascular risk level — better predictor of metabolic disease than BMI alone→ Body Shape Calculator—Find your body type — hourglass, pear, apple, rectangle, or inverted triangle→ BMR Calculator—Basal metabolic rate with 3 formulas: Mifflin-St Jeor, Harris-Benedict, Katch-McArdle→ Weight Loss % Calculator—Calculate what % of your starting weight you've lost — progress bar and milestones→ Blood Pressure Calculator—Check if your BP is normal, elevated, or high — AHA 2017 guidelines, MAP and pulse pressure→ BAC Calculator—Estimate blood alcohol content by drinks, weight, and time — Widmark formula and sober-up timer→

Nutrition & Diet

10 tools

Calorie Calculator—Daily calorie needs (TDEE) to lose, maintain, or gain weight — Mifflin-St Jeor formula→ Macro Calculator—Daily protein, carbs, and fat targets for fat loss, maintenance, or muscle gain→ Calorie Deficit Calculator—How long to reach your goal weight — enter current intake vs TDEE and see the timeline→ Weight Gain Calculator—Calorie surplus to gain weight or build muscle — week-by-week projections→ Protein Calculator—Daily protein needs based on weight, activity level, and goals→ Keto Calculator—Ketogenic diet macros — daily fat, protein, and net carb targets for your weight and goals→ Water Intake Calculator—Daily hydration needs based on weight, activity level, and climate→ Fiber Calculator—Daily fiber intake recommendations by age and sex — high-fiber foods list included→ Vitamin D Calculator—Recommended Vitamin D intake by age and risk factors — sunlight exposure guide→ Caffeine Calculator—Track daily caffeine vs the FDA 400mg limit — includes caffeine clearance timeline→

Fitness & Performance

6 tools

Pace Calculator—Running pace, finish time, or distance for any race — 5K to marathon splits→ Target Heart Rate Calculator—Maximum heart rate and all 5 training zones for fat burn, cardio, and peak performance→ One Rep Max Calculator—Estimate your 1RM for any lift using 7 formulas — full training percentages table→ VO2 Max Calculator—Estimate cardiovascular fitness via 1-mile walk, 1.5-mile run, or heart rate method→ Sleep Calculator—Best bedtime or wake-up time based on 90-minute sleep cycles — never wake up groggy→ Sleep Debt Calculator—Weekly sleep debt from nightly hours — color-coded chart and recovery plan→

Women's Health

5 tools

Pregnancy Due Date Calculator—Estimated due date, weeks pregnant, and full trimester timeline from LMP or conception date→ Ovulation Calculator—Find your fertile window and best days to conceive — calendar view and 3 future cycles→ Period Calculator—Predict your next 12 periods, ovulation days, and fertile windows→ Pregnancy Weight Gain Calculator—How much weight to gain during pregnancy by pre-pregnancy BMI — IOM 2009 week-by-week guide→ Fertility by Age Calculator—Monthly conception chances by age — miscarriage rates and IVF success rates included→

Mental Health Screening

3 tools

⚕️ These are validated clinical screening tools, not diagnostic instruments. A score above the clinical threshold does not constitute a diagnosis. Please speak with a mental health professional if you have concerns about your results.

GAD-7 Anxiety Scale—Generalized Anxiety Disorder-7 questionnaire — score anxiety severity over the past 2 weeks. Clinical cut-off at 10.→ PHQ-9 Depression Scale—Patient Health Questionnaire-9 — DSM-5 based depression severity score over the past 2 weeks. Max score 27.→ PCL-5 PTSD Checklist—PTSD Checklist for DSM-5 — 20-item trauma symptom severity score over the past month. Cut-off at 31–33.→

Baby & Child

2 tools

BMI Calculator for Kids—Child BMI percentile for ages 2–19 using CDC growth charts — underweight to obese classifications→ Baby Formula Calculator—How much formula per feeding and per day by age and weight — AAP guidelines→ Height Calculator—Predict your child's adult height using mid-parental height formula and Khamis-Roche method→