Free Health &amp; Fitness Calculators

Set calorie target Check protein needs

Build Muscle

Estimate maintenance, add a controlled surplus, and dial in protein and macros.

Check BMI BMI vs body fat

Improve Body Composition

Compare screening tools with more precise body-composition metrics.

Find training zones Estimate VO2 max

Train Smarter

Use heart-rate zones, pace, and VO2 max together to guide endurance work.

Body Composition Calculators

BMI Calculator

Calculate your Body Mass Index to assess your weight relative to your height.

Body Fat Calculator

Estimate your body fat percentage using the U.S. Navy circumference method.

Ideal Weight Calculator

Find your ideal weight range using four clinically recognized formulas.

Lean Body Mass Calculator

Calculate your lean body mass and estimated body fat using the Boer formula.

Waist-to-Hip Ratio Calculator

Assess your health risk with the WHO waist-to-hip ratio guidelines.

Army Body Fat Calculator

Calculate your body fat percentage using the U.S. Army tape test standards.

FFMI Calculator

Calculate your Fat-Free Mass Index to assess muscular development relative to height.

Body Type Calculator

Determine your somatotype (ectomorph, mesomorph, or endomorph) with training and nutrition guidance.

Waist-to-Height Ratio Calculator

Assess your health risk using the WHO waist-to-height ratio threshold of 0.5.

Body Roundness Index Calculator

Calculate your Body Roundness Index to assess body shape and health risk from waist and height.

Relative Fat Mass Calculator

Estimate your body fat percentage using the Woolcott & Bergman RFM formula from height and waist.

Muscle Gain Potential Calculator

Estimate your maximum muscular bodyweight using the Casey Butt frame-size model.

Skinfold Body Fat Calculator

Calculate your body fat percentage using Jackson-Pollock 3-site and 7-site caliper formulas.

Body Surface Area Calculator

Calculate your body surface area using DuBois, Mosteller, and Haycock formulas.

Nutrition & Diet Calculators

TDEE Calculator

Estimate your Total Daily Energy Expenditure based on activity level.

BMR Calculator

Calculate your Basal Metabolic Rate — the calories your body burns at rest.

Calorie Calculator

Find your daily calorie goal for weight loss, maintenance, or gain.

Macro Calculator

Distribute your daily calories across protein, carbs, and fat.

Protein Intake Calculator

Calculate your daily protein requirements based on weight and activity.

Water Intake Calculator

Calculate your recommended daily water intake based on weight and activity.

Calories Burned Calculator

Estimate calories burned during exercise using MET-based calculations.

Fiber Intake Calculator

Find your recommended daily fiber intake based on age, sex, and diet.

Calorie Deficit Calculator

Plan your calorie deficit with TDEE-based targets, safety floors, and weight loss projections.

Keto Calculator

Calculate your keto macros with standard, moderate, and high-protein ratio presets.

Steps to Calories Calculator

Convert your daily step count into an estimated calorie burn based on weight and stride.

Walking Calories Calculator

Estimate calories burned while walking based on speed, duration, and incline.

Carbohydrate Intake Calculator

Calculate your daily carbohydrate target based on your TDEE and preferred carb level.

Fat Intake Calculator

Find your recommended daily fat intake in grams based on your calorie target and dietary preference.

Weight Loss Timeline Calculator

Project your weight loss timeline week by week with TDEE-based calorie targets and realistic projections.

Weight Gain Calculator

Calculate your calorie surplus and macro split for healthy, controlled weight gain.

Lean Bulk Calculator

Plan a lean bulk with an experience-adjusted calorie surplus and optimized protein, carb, and fat targets.

Intermittent Fasting Calculator

Calculate your eating and fasting windows for 16:8, 18:6, 20:4, and OMAD protocols.

Body Recomposition Calculator

Get calorie cycling targets and protein goals for simultaneous fat loss and muscle gain.

Vitamin D Calculator

Estimate your vitamin D supplement dose based on body weight, blood levels, and sun exposure.

Magnesium Calculator

Find your ideal magnesium dose and form recommendation based on your health goal.

Creatine Loading Calculator

Calculate your creatine loading and maintenance doses with saturation timeline and cost estimate.

Caffeine Calculator

Calculate your safe daily caffeine limit and see how many servings of your favorite beverages fit within it.

Glycemic Load Calculator

Calculate the glycemic load of foods and meals based on glycemic index and carbohydrate content.

Electrolyte Calculator

Find your daily sodium, potassium, and magnesium targets based on activity level and diet type.

Protein Timing Calculator

Optimize your protein distribution across meals for muscle protein synthesis based on the Schoenfeld model.

Alcohol Calorie Calculator

Calculate the calories in alcoholic beverages based on type, volume, and ABV.

Sugar Intake Calculator

Check your daily added sugar intake against WHO and AHA recommended limits.

Supplement Stack Calculator

Build a personalized supplement stack based on your goals, diet, and body weight with evidence-tiered recommendations.

GLP-1 Protein Calculator

Calculate your daily protein target for muscle preservation on GLP-1 medications.

NMN/NR Dose Guide

Reference guide for NMN and NR doses used in human clinical research. Not a recommendation — always consult your doctor before supplementing.

GLP-1 Muscle Loss Risk Calculator

Estimate your muscle preservation risk on GLP-1 medications based on weight loss rate, protein intake, and resistance training.

Creatine Loading Calculator

Calculate your creatine loading phase dose and maintenance dose based on bodyweight, citing Hultman et al. 1996.

Caffeine Dose Calculator

Calculate the research-based pre-exercise caffeine dose range (3–6 mg/kg) for performance, with FDA daily limit flagging.

Peptide Dose Reference Guide

Reference doses from published research studies for BPC-157, TB-500, CJC-1295, Ipamorelin, and Semaglutide. Educational only.

Goal Weight Timeline Calculator

Estimate how long it may take to reach your goal weight at a given daily calorie intake, based on TDEE and 3,500 kcal per pound math.

Reverse Diet Calculator

Build a week-by-week calorie ramp after a cut to recover maintenance calories with minimal fat regain.

Paleo Macro Calculator

Calculate paleo macros from TDEE using a 30% protein, 30% carb, 40% fat split with a paleo food focus.

Mediterranean Macro Calculator

Calculate Mediterranean-diet macros using a 20% protein, 50% carb, 30% fat split with olive oil, fish, and whole grains.

Vegan Macro Calculator

Calculate plant-based macros with a 20% protein, 55% carb, 25% fat split and fortification guidance.

Carnivore Macro Calculator

Calculate carnivore-style macros using a 35P / 5C / 60F split. Informational framework — long-term data is limited.

Omega-3 / Omega-6 Ratio Calculator

Sum a weekly food log to estimate your omega-6 : omega-3 ratio and compare to Mediterranean, ancestral, and Western baselines.

Macros Per Meal Calculator

Split your daily protein, carb, and fat targets across meals with even, protein-forward, carb-around-workout, or IF 2-meal strategies.

Fitness & Exercise Calculators

One Rep Max Calculator

Estimate your one-rep max using Epley, Brzycki, and Lombardi formulas.

Heart Rate Zone Calculator

Find your five training heart rate zones using the Karvonen formula.

Pace Calculator

Calculate your running pace, speed, and predicted race finish times.

VO2 Max Calculator

Estimate your VO2 max and aerobic fitness level with the Cooper or Rockport test.

Race Time Predictor

Predict finish times for common race distances using the Riegel formula.

Strength Standards Calculator

Compare your lifts to population strength standards by sex and bodyweight for bench, squat, deadlift, and OHP.

Bench Press Calculator

Estimate your bench press one-rep max and get a full training load table with rep ranges.

Squat Calculator

Estimate your squat one-rep max using Epley and Brzycki formulas with a training load chart.

Running Calorie Calculator

Estimate calories burned while running based on pace, duration, weight, and incline.

Cycling Calorie Calculator

Estimate calories burned while cycling based on speed, duration, and body weight.

Max Heart Rate Calculator

Estimate your maximum heart rate using Fox, Tanaka, and Gulati formulas with target training zones.

Fat Burning Zone Calculator

Find your fat burning heart rate zone using standard or Karvonen methods.

Deadlift Calculator

Estimate your deadlift one-rep max using Epley and Brzycki formulas with a training load chart.

Wilks / DOTS Score Calculator

Calculate your Wilks-2 and DOTS scores to compare powerlifting performance across bodyweights.

IPF GL Points Calculator

Calculate your IPF Goodlift (GL) Points to compare powerlifting performance across bodyweight classes using the 2020 IPF coefficient.

Training Load / ACWR Calculator

Calculate your Acute:Chronic Workload Ratio (ACWR) to assess injury risk and guide training load management over a 28-day period.

Workout Volume Calculator

Track your training volume per muscle group with RP volume landmark classifications.

Swimming Calorie Calculator

Estimate calories burned while swimming based on stroke type, intensity, and duration.

Exercise Hydration Calculator

Calculate your sweat rate and fluid replacement targets using measured or estimated methods.

Grip Strength Standards Calculator

Compare your grip strength to Bohannon 2019 normative data with a longevity risk assessment.

Zone 2 Heart Rate Calculator

Find your Zone 2 aerobic base heart rate range using Maffetone, Karvonen, or percent-of-max methods.

Steps to Goal Weight Calculator

Project how long to reach your goal weight at a given daily step target, using body-weight-adjusted energy math.

Heart Rate Recovery Calculator

Calculate your 1-minute or 2-minute heart rate recovery after exercise to assess cardiovascular fitness.

Women's Health Calculators

Pregnancy Weight Gain Calculator

Find your recommended pregnancy weight gain based on IOM guidelines.

Due Date Calculator

Estimate your due date from your last menstrual period, conception, or IVF transfer date.

Ovulation Calculator

Estimate your ovulation date and fertile window based on your menstrual cycle.

Period Calculator

Track your menstrual cycle with next period predictions, ovulation estimates, and a 6-cycle forecast.

Conception Calculator

Estimate your conception date from your due date, last period, or birth date.

Breastfeeding Calorie Calculator

Calculate your daily calorie and macro needs while breastfeeding based on TDEE and lactation stage.

Perimenopause Symptom Score

Assess perimenopause symptom severity using the validated Menopause Rating Scale (MRS) with somatic, psychological, and urogenital subscales.

Basal Body Temperature Chart

Chart your basal body temperature to detect ovulation with coverline and thermal shift analysis.

Menstrual Cycle Phase Calculator

Identify your current menstrual cycle phase — menstrual, follicular, ovulation, or luteal — based on your last period date and average cycle length.

Postpartum Macro Calculator

Estimate postpartum calorie and macronutrient targets for recovery and breastfeeding using Mifflin-St Jeor TDEE with evidence-based lactation additions.

Menopause Kupperman Index Calculator

Score your menopausal symptom burden using the validated Kupperman Menopausal Index — rate 11 symptoms with weighted scoring.

General Health Calculators

Biological Age Calculator

Estimate your biological age based on lifestyle factors including exercise, sleep, diet, and stress.

Gut Health Score Quiz

Score your gut health across 10 lifestyle factors — from fiber intake and fermented foods to stress and sleep.

Sleep Calculator

Find optimal bedtimes or wake times based on 90-minute sleep cycles.

BAC Calculator

Estimate your blood alcohol content using the Widmark formula.

Sleep Debt Calculator

Track your cumulative sleep debt over 7 days and estimate recovery time.

Diabetes Risk Calculator

Assess your type 2 diabetes risk using the ADA risk score based on age, BMI, family history, and lifestyle.

Heart Disease Risk Calculator

Estimate your 10-year cardiovascular disease risk using the Framingham Risk Score.

Blood Pressure Calculator

Classify your blood pressure reading using AHA/ACC 2017 guidelines with stage-specific guidance.

Cholesterol Ratio Calculator

Calculate your Total/HDL, LDL/HDL, and triglyceride/HDL ratios with cardiovascular risk assessment.

A1C Calculator

Convert between A1C percentage and estimated average glucose using the ADAG formula.

Metabolic Syndrome Calculator

Evaluate metabolic syndrome risk using the IDF/AHA five-criteria checklist.

HOMA-IR Calculator

Calculate your insulin resistance score using fasting glucose and insulin levels.

PHQ-9 Depression Screening

Screen for depression severity using the validated PHQ-9 questionnaire with crisis resources.

Perceived Stress Scale (PSS-10)

Assess your perceived stress level using the validated Cohen PSS-10 questionnaire.

Fitness Age Calculator

Estimate your fitness age based on resting heart rate, activity level, and body measurements.

Child & Teen BMI Percentile Calculator

Calculate BMI percentile for children and teens ages 2-20 using CDC growth charts.

Quit Smoking Calculator

Track your health recovery timeline and financial savings since quitting smoking.

Sitting Time / Sedentary Risk Calculator

Assess your sedentary risk score based on daily sitting hours, exercise, and break frequency.

Recovery Score Estimator

Rate your sleep, soreness, mood, and resting HR to get a composite 0-100 recovery score with readiness guidance.

HRV Readiness Guide

Enter your current HRV and personal baseline to understand what your heart rate variability may suggest about your recovery and readiness.

Telomere Health Score

Estimate your telomere health profile based on lifestyle factors shown to correlate with telomere length in research. Educational proxy — not a clinical test.

eGFR Calculator

Estimate your kidney function (eGFR) from serum creatinine, age, and sex using the CKD-EPI 2021 race-free equation.

LDL Particle Size Guide

Understand your LDL-C result and learn the difference between LDL-C and LDL particle number (LDL-P) — and what to discuss with your doctor.

GLP-1 Eligibility Calculator

Check whether your BMI and conditions align with FDA label criteria for Wegovy, Zepbound, Saxenda, or diabetes-class GLP-1 medications.

GLP-1 Dosage Schedule Calculator

Look up the FDA-label titration schedule for Wegovy, Zepbound, Mounjaro, and Saxenda week by week.

GLP-1 Weight Loss Projector

Project realistic mean weight loss on semaglutide, tirzepatide, or liraglutide using STEP 1, SURMOUNT-1, and SCALE trial data.

GLP-1 Cost Calculator

Compare monthly and annual GLP-1 cost across branded pharmacy, compounded telehealth, and Medicare-covered sources.

LDL/HDL Ratio Calculator

Calculate your LDL-to-HDL cholesterol ratio and assess cardiovascular risk using AHA/NCEP ATP III thresholds.

QUICKI Calculator

Calculate your Quantitative Insulin Sensitivity Check Index (QUICKI) from fasting insulin and glucose values.

Sleep & Recovery Calculators

Caffeine Sleep Optimizer

Estimate residual caffeine at bedtime and a safe cutoff time using a 5-hour half-life decay model.

Aging & Longevity Calculators

Sauna Protocol Calculator

Score your weekly dry-sauna protocol against KIHD cohort tiers for cardiovascular and dementia associations.

Osteoporosis Risk Calculator

Screen for osteoporosis fracture risk using FRAX-inspired clinical factors: age, sex, BMI, fracture history, and lifestyle.

Popular Guides

Short, practical articles that explain the numbers behind the calculators and help you choose the right next step.

View all guides

Which Health Calculator Should You Use First?

A simple starting map based on weight loss, muscle gain, body composition, and cardio goals.

How Many Calories Should I Eat to Lose Weight?

A practical way to set a calorie target using your TDEE and a sustainable deficit.

BMI vs. Body Fat Percentage

Understand when BMI helps, when it fails, and why body fat percentage often matters more.

BMR vs. TDEE

Learn which number to use when planning calories for loss, maintenance, or gain.