Health & Medical calculators
BMI, BMR, body fat, pediatric dosing, and pregnancy timelines. Browser-only by design - we never see the numbers you type.
All health & medical tools
36 tools, each runs locally in your browser. Click any card to open it.
A1C to Blood Glucose Calculator takes height, weight, age, sex, activity and returns the matching a1c to blood glucose…
Adult Height Predictor takes height, weight, age, sex, activity and returns the matching adult height predictor result…
Anion Gap Calculator takes height, weight, age, sex, activity and returns the matching anion gap result. Runs entirely…
Blood Alcohol (BAC) Calculator computes estimated BAC, time to sober from drinks consumed, weight, sex, hours since fi…
Blood Pressure Calculator takes height, weight, age, sex, activity and returns the matching blood pressure result. Run…
BMI Calculator computes BMI value, category band from height, weight. Runs entirely in your browser. No login, no trac…
BMI vs Body Fat Comparison computes BMI value, category band from height, weight. Runs entirely in your browser. No lo…
BMR Calculator takes height, weight, age, sex, activity and returns the matching bmr result. Runs entirely in your bro…
Body Fat 3-Site Skinfold Calculator computes body fat %, category from sex, age, weight, neck, waist, hip. Runs entire…
Body Fat Calculator computes body fat %, category from sex, age, weight, neck, waist, hip. Runs entirely in your brows…
Body Fat Percentage Calculator (Navy) computes body fat %, category from sex, age, weight, neck, waist, hip. Runs enti…
Body Surface Area Calculator takes numbers, ranges, parameters and returns the matching body surface area result. Runs…
Bone mass typically 3-5 percent of body weight.
Calorie Calculator (BMR & TDEE) computes daily calorie target from age, sex, weight, height, activity level. Runs …
Calorie Deficit Calculator computes daily calorie target from age, sex, weight, height, activity level. Runs entirely …
Calories Burned Running Calculator computes daily calorie target from age, sex, weight, height, activity level. Runs e…
Calories Burned Walking Calculator computes daily calorie target from age, sex, weight, height, activity level. Runs e…
Child-Pugh Score Calculator takes height, weight, age, sex, activity and returns the matching child-pugh score result.…
Cholesterol Ratio Calculator takes height, weight, age, sex, activity and returns the matching cholesterol ratio resul…
Creatinine Clearance (Cockcroft-Gault) takes height, weight, age, sex, activity and returns the matching creatinine cl…
eGFR Calculator (CKD-EPI 2021) takes height, weight, age, sex, activity and returns the matching egfr calculator (ckd-…
Exercise Calorie by Activity computes daily calorie target from age, sex, weight, height, activity level. Runs entirel…
Hiking Calorie Calculator computes daily calorie target from age, sex, weight, height, activity level. Runs entirely i…
Ideal Body Weight Calculator (Devine) takes height, weight, age, sex, activity and returns the matching ideal body wei…
Kids BMI Percentile Calculator computes BMI value, category band from height, weight. Runs entirely in your browser. N…
Lean Body Mass Calculator takes height, weight, age, sex, activity and returns the matching lean body mass result. Run…
Pediatric Medication Dosage computes age in years/months/days from birth date, target date. Runs entirely in your brow…
Next three periods plus fertile window for each cycle.
Protein Intake Calculator takes height, weight, age, sex, activity and returns the matching protein intake result. Run…
Sleep Debt Calculator takes height, weight, age, sex, activity and returns the matching sleep debt result. Runs entire…
Smoothie Calorie Calculator computes daily calorie target from age, sex, weight, height, activity level. Runs entirely…
A Streaming Bundle vs Individual Calculator computes streaming bundle vs individual from the inputs you provide.
TDEE Calculator (Mifflin-St Jeor) takes height, weight, age, sex, activity and returns the matching tdee calculator (m…
Water Intake Calculator takes height, weight, age, sex, activity and returns the matching water intake result. Runs en…
😴 Sleep Cycle Calculator takes height, weight, age, sex, activity and returns the matching 😴 sleep cycle result. Run…
amoxicillin pediatric dose, mg/kg amoxicillin, AAP otitis media, strep pharyngitis, CAP child antibiotic amoxicillin p…
About health & medical
Health and medical calculators cover the formulas a primary care physician, dietitian, or trainer uses daily: BMI (WHO and Asian-Pacific cutoffs), BMR (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle), TDEE with PAL multipliers, body fat (Navy method, Jackson-Pollock 3/7-site, US Army), pediatric weight-based dosing, Body Surface Area (Du Bois, Mosteller, Haycock), Anion Gap, Creatinine Clearance (Cockcroft-Gault), MELD score, and pregnancy due date (Naegele's rule + ultrasound-adjusted).
Use these tools to answer: what's my TDEE at my current activity level, what BMI bracket am I in given the WHO vs Asian cutoffs, what's the safe amoxicillin dose for a 22 kg child, how do I estimate body fat without DEXA, what's my creatinine clearance for renal dose adjustment, and how many calories should I cut to lose 0.5 kg per week safely.
Sources: WHO BMI cutoffs, ADA fat guidelines, Mayo Clinic dosing references, ACOG pregnancy dating standards, KDIGO renal staging. Tools are decision-support for screening; clinical use should always be cross-checked with a licensed prescriber.
Common use cases
Real scenarios where the health & medical calculators in this category earn their keep.
Cutting weight on a deficit
Compute TDEE using Mifflin-St Jeor BMR × activity multiplier, then subtract 300-500 kcal for sustainable 0.3-0.5 kg per week loss. Higher deficits risk LBM loss.
Pediatric medication dosing
Weight-based dosing in mg/kg for amoxicillin, ibuprofen, acetaminophen, and other common pediatric drugs. Output mL of standard suspensions plus the round-up to a safe dose.
BMI screening with the right cutoffs
WHO cutoffs (18.5 / 25 / 30) for most populations; lower Asian-Pacific cutoffs (23 overweight, 27.5 obese) for South Asian and East Asian patients per WHO 2004.
Estimating eGFR for renal dosing
Cockcroft-Gault (mL/min) for drug dose adjustment, plus CKD-EPI (mL/min/1.73m²) for CKD staging. Both use serum creatinine, age, sex, and weight.
Pregnancy due date
Naegele's rule: LMP + 280 days. Ultrasound-adjusted EDD if the first-trimester CRL differs by more than 5-7 days. The pregnancy tool runs both methods.
Key terms
Glossary for the formulas and conventions these tools use.
- BMI
- Body Mass Index. Weight (kg) divided by height (m) squared. Population-level screen for under- or overweight; misleading at extremes of muscle mass.
- BMR
- Basal Metabolic Rate. Calories burned at complete rest. Mifflin-St Jeor (1990) is the current best-validated equation for healthy adults.
- TDEE
- Total Daily Energy Expenditure. BMR multiplied by an activity factor (1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 active, 1.9 very active).
- BSA
- Body Surface Area. Used for chemotherapy dosing, cardiac index, and pediatric IV fluids. Mosteller formula is the easiest at the bedside.
- eGFR
- estimated Glomerular Filtration Rate. Marker of kidney function. CKD-EPI 2021 (no race coefficient) is the current standard for CKD staging.
- Anion gap
- Sodium - (Chloride + Bicarbonate). Normal 8-12 mEq/L. Elevated gap narrows the differential for metabolic acidosis (MUDPILES, KULT).
- Cockcroft-Gault
- Creatinine clearance estimate in mL/min. Used for drug dose adjustment because FDA dose labels were validated against it (not eGFR).
Frequently asked questions
Short answers to the most common health & medical questions.