Health Tools

A free suite of browser health tools. Estimate body fat and BMI, time your sleep by cycle, track your measurements over time, plan lifting and cardio, dial in calories and macros with TDEE and BMR, and run bedside clinical calculators like eGFR and anion gap. Everything runs in your browser, and nothing is ever uploaded.

Body composition & BMI

Estimate your body fat percentage, or check your Body Mass Index against a healthy range.

Fitness & training

Plan your lifting — estimate your strength and turn it into working weights.

Lifestyle

Everyday health estimates for planning and awareness — not medical advice.

Nutrition & calories

Work out the calories you burn and how to eat for your goal — all built on the Mifflin-St Jeor equation.

Pregnancy

Estimate your due date, or find out how far along you are, week by week.

Medical & lab calculators

Clinical calculators grouped by system — kidney and electrolytes, heart and vascular risk, clots and lungs, liver, and more — that pair with our lab unit converters. Reference tools, not medical advice.

Kidney & electrolytes

Heart & vascular risk

Atrial fibrillation & bleeding

Clots & lungs

Liver

Diabetes

Lipids

Blood & inflammation

Body measurements

Bedside scores

Free

Glasgow Coma Scale

Score consciousness from the best eye, verbal and motor responses (total 3–15) with the mild, moderate or severe band.

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Free

qSOFA

Quick bedside sepsis screen from respiratory rate, mental status and blood pressure, with the ≥ 2 high-risk threshold.

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Free

Centor Score

Modified Centor / McIsaac strep-throat probability from four findings plus age, with the testing recommendation.

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Free

NEWS2

National Early Warning Score 2 from six bedside observations, with the aggregate score and clinical-risk band.

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Free

Shock Index

Heart rate ÷ systolic blood pressure — an early bedside marker of circulatory compromise (> 0.9 concerning).

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Free

Alvarado Score

MANTRELS clinical score for the likelihood of acute appendicitis (0–10), with the interpretation band.

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Free

Glasgow-Blatchford

Upper GI bleed risk from urea, haemoglobin and vital signs (0–23); a score of 0 is very low risk.

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Free

CIWA-Ar

Alcohol withdrawal severity from ten items (0–67) with a severity band for symptom-triggered care.

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Free

HEART Score

Major adverse cardiac event risk in emergency-department chest pain from History, ECG, Age, Risk factors and Troponin (0–10).

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Free

SOFA Score

Sequential Organ Failure Assessment across six organ systems (0–24), used in sepsis and critical care.

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Free

SF Syncope Rule

CHESS screen after a faint (syncope) for serious short-term risk — congestive failure, haematocrit, ECG, breathlessness, low BP.

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Free

Bishop Score

Cervical favourability before induction of labour (0–13) from dilation, effacement, station, consistency and position.

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Free

NIHSS (Stroke)

NIH Stroke Scale severity across 11 items (0–42), with the minor-to-severe band for acute stroke.

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Dosing & pharmacology

BMI vs body fat

BMI (Body Mass Index) is a quick proxy calculated from just your height and weight. It's useful for a fast, population-level check, but it can't tell muscle from fat — a muscular athlete and a sedentary person of the same height and weight can land on the same BMI while having very different body compositions.

Body fat percentage goes a step further and estimates your actual composition — how much of your weight is fat versus lean mass (muscle, bone, organs, water). The Body Fat Calculator gets there with U.S. Navy tape measurements, or a rougher BMI-based estimate when you don't have a tape measure handy. Use the BMI Calculator first for a quick screen, then the Body Fat Calculator for a closer look at composition.