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Your Health Calculator Hub

30+ precision health tools built for athletes, biohackers, and anyone serious about their wellbeing. Every formula is research-validated and fully explained.

30+

Calculators

5

Categories

100%

Free

🔬 Research-validated formulas

📏 Metric & Imperial units

🔒 No data stored or shared

⚡ Instant results, no account needed

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🏋️

Cluster 01

Performance & Physique

For powerlifters, bodybuilders, and athletes tracking strength and body composition.

Wilks · DOTS · IPF GL Calculator

Calculate all three major powerlifting coefficients simultaneously and compare strength across weight classes.

PowerliftingStrength

FFMI — Fat-Free Mass Index

Measure lean muscle relative to height and find your distance from the natural genetic ceiling.

BodybuildingBody Comp

1RM Percentages Table

Generate a full training table from 50–100% of your one-rep max for any lift. Includes RPE and rep ranges.

ProgrammingStrength

Navy Body Fat Calculator

Official US DoD circumference method — just a tape measure and 3–4 body measurements. No calipers needed.

Body FatMilitary

Ideal Racing Weight

Find your peak performance weight for running, triathlon, or cycling using the Fitzgerald method.

RunningTriathlon

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Cluster 02

Biohacking & Longevity

For those optimizing lifespan, biological age, and long-term health span metrics.

Biological Age Estimator

Estimate your real biological age from lifestyle, sleep, exercise, and biomarker inputs using validated algorithms.

LongevityBiohacking

VO₂ Max Estimator

Estimate maximal aerobic capacity from a 1.5-mile run, resting HR, or Cooper test. The #1 longevity biomarker.

LongevityCardio

Heart Rate Training Zones

Calculate all 5 heart rate training zones using Karvonen, percentage, and lactate threshold methods.

Sleep Cycle Calculator

Find the best bedtime or wake time based on 90-minute REM cycles so you wake between cycles, not in one.

Grip Strength Percentile

See where your grip strength ranks by age and sex. Grip strength is one of the strongest predictors of all-cause mortality.

LongevityStrength

Fasting Window Planner

Plan your 16:8, 18:6, or OMAD fasting window with a visual eating/fasting timeline and autophagy onset estimate.

FastingBiohacking

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Cluster 03

Nutrition & Metabolic

Calorie, macro, and metabolic calculators for fat loss, muscle gain, and sports performance.

TDEE Calculator

Total Daily Energy Expenditure with all 5 activity multipliers and goal-based calorie targets (cut/maintain/bulk).

Macro Calculator

Get personalized protein, fat, and carb targets based on your goal, body composition, and training style.

Protein Intake Calculator

Optimal daily protein based on lean mass, activity, age, and goal — cross-referenced with ISSN and ACSM guidelines.

Alcohol Metabolism Calculator

Estimate time to sobriety, hidden calories, and sleep disruption impact from alcohol consumption.

NutritionLifestyle

Caffeine Half-Life Calculator

Find out when your last cup of coffee will stop affecting your sleep using caffeine's 5–7 hour half-life.

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Cluster 04

Preventative & Clinical

Evidence-based clinical screening tools and risk calculators for proactive health management.

BMI Calculator (with Context)

BMI with detailed context — including why it's limited, plus body fat % and waist-to-height ratio for a fuller picture.

Waist-to-Height Ratio

A better metabolic health predictor than BMI. WHO recommends keeping waist below half your height.

Heart HealthClinical

Blood Pressure & MAP

Classify your blood pressure per AHA guidelines and calculate Mean Arterial Pressure (MAP).

Heart HealthClinical

Vitamin D & Sun Exposure

Calculate sun exposure needed for vitamin D synthesis based on skin type, latitude, and season.

VitaminsPrevention

Daily Hydration Calculator

Personalized daily water intake based on weight, climate, activity level, and sweat rate during exercise.

HydrationHealth

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Cluster 05

Wildcard & Viral Calculators

High-shareability tools that answer the specific health questions everyone Googles.

Calories Burned Walking

Exact calories burned walking by weight, pace, terrain, and distance — including a steps-to-calories converter.

WalkingCalories

Bench Press Standards

"How much should I bench press?" — See exactly how you compare by age, weight, and training experience.

Ideal Body Weight Calculator

4 formulas side-by-side: Robinson, Miller, Devine, and Hamwi — with an honest discussion of what "ideal" really means.

Resting Metabolic Rate (RMR)

Calculate your BMR/RMR using 4 equations — Mifflin-St Jeor, Harris-Benedict, Katch-McArdle, and Cunningham.

Push-Up Standards by Age

See how your push-up count compares to age and sex norms from fitness research and military standards.