Health assessment calculators,
grounded in research.

Classic health metric to assess if your weight is in a healthy range for your height.

Simple yet powerful health screening tool that may predict health risks better than BMI.

Estimate your ideal body weight using four established medical formulas based on height and gender.

Calculate your 5 heart rate training zones for fat burning, cardio fitness, and peak performance.

Find the best times to sleep and wake up based on 90-minute sleep cycles to feel refreshed.

Calculate how much water you should drink daily based on your weight, activity level, and climate.

Estimate your maximum heart rate using four validated scientific formulas with training zone preview.

Calculate waist-to-hip ratio and compare against WHO risk thresholds for metabolic disease.

Convert systolic and diastolic blood pressure to mean arterial pressure with clinical ranges.

Compare your grip strength against age and sex norms from the NIH Toolbox dataset.

Estimate ovulation and your fertile window based on your last period and cycle length.

Convert A1C percentage to estimated average glucose with diabetic and prediabetic ranges.

Plan your eating window with 16:8, 18:6, 20:4, OMAD, or 5:2 protocols.

Classify your body frame from height and wrist circumference — useful context for ideal-weight targets.

Convert running pace between km and mile units, see speed in km/h and mph, plus race splits.

Estimate calories from alcoholic drinks including mixer calories. See your beer-equivalent total.

Estimate how much caffeine remains in your system hour by hour — plan bedtime around your intake.

Validated 8-question screener for excessive daytime sleepiness — flags possible sleep disorders.

Compare your arm span to your height — a known advantage in climbing, swimming, and basketball.

Plan pre-workout meals, snacks, and recovery windows around your training session.

Convert daily steps into calories burned, distance walked, and active minutes using stride length and MET values.

Estimate walking and running stride length from height — useful for calibrating step counters.

Find the heart rate zone where the body draws the largest share of fuel from fat.

Estimate safe sun exposure time and vitamin D production based on skin type, UV index, and exposed area.

Estimate trail duration from distance and elevation gain using Naismith's rule with a fitness adjustment.

Find out how many calories you burn per day based on your activity level using Mifflin-St Jeor.

Calculate your resting calorie burn using Mifflin-St Jeor and Harris-Benedict equations.

Calculate daily macronutrient targets with multiple preset splits for your fitness goals.

Find your optimal daily protein intake with per-meal targets and food equivalents.

Evaluate muscle mass relative to height. Perfect for athletes and fitness enthusiasts.

Calculate body fat percentage using Navy, Jackson-Pollock, or BMI methods.

Estimate your one-rep max using 5 validated formulas with training load percentages.

Calculate running pace, finish time, and race splits for 5K, 10K, half, and marathon.

Calculate your daily calorie target for weight loss with estimated timeline to goal weight.

Calculate your body fat percentage using the U.S. Navy tape measure method with fitness category.

Calculate your lean body mass (muscle, bone, organs) from your weight and body fat percentage.

Compare your bench, squat, deadlift, and press against normative strength data by bodyweight.

Calculate Wilks score from your squat, bench, and deadlift totals — the classic powerlifting metric.

Calculate DOTS — the modern replacement for Wilks — from your powerlifting total and bodyweight.

Calculate VDOT from any race time, then get equivalent times and training paces across distances.

Predict your race time at any distance from one known result using the validated Riegel formula.

Compare your BMR to the average for your age — a quick engagement check of metabolic fitness.

Calculate calories burned from 39+ activities using the Compendium of Physical Activities MET values.

Calculate functional threshold power and W/kg from a 20-min, 8-min, or ramp test with 7 power zones.

Calculate body surface area using three validated formulas. Used in medicine for drug dosing.

Track healthy pregnancy weight gain based on pre-pregnancy BMI using the IOM guidelines.

Convert FTP and bodyweight into W/kg — the primary cycling performance metric across tiers.

Validated 9-question screener for depression severity. Widely used in primary care and mental health.

Validated 7-question screener for generalized anxiety disorder severity over the past 2 weeks.

Estimate hourly sweat loss from a pre/post weigh-in and get a personal hydration replacement target.

Quantify session training stress using the validated session RPE method — RPE × duration.

Measure your 1-minute heart rate recovery — a clinically validated marker of cardiovascular fitness.

Add up your weekly activity load and see whether you meet WHO physical activity guidelines.

Estimate your lactate threshold HR (88% max + Karvonen) and optionally derive threshold pace from a 10K time.

Predict 5K, 10K, half marathon, and marathon times from a single all-out mile using Galloway's method.

Plan even, negative, and positive race splits for any distance and goal time with cumulative targets.

Calculate your age-graded race percentage for 5K through marathon and see your competitive class.

Validated 10-question screener for perceived stress over the past month, with severity classification.

Estimate your VO2 max with the Cooper 12-minute run or 1.5-mile test. See your fitness classification.

Discover your biological age using advanced epigenetic biomarkers and blood test results.

Estimate your 10-year risk of heart attack or stroke using the ACC/AHA Pooled Cohort Equations.

Estimate skeletal muscle mass normalized to height — the primary screening metric for sarcopenia.

Estimate VO2 max and METs from total time on a Bruce Protocol treadmill stress test using validated regressions.