Calculators
Thirty-one evidence-based tools — calories, body composition, diabetes, cardio risk, diet patterns, training, sleep. Every formula is cited. Every range comes from peer-reviewed research.
Calories & energy
TDEE Calculator
Total Daily Energy Expenditure with the clinical-grade Mifflin-St Jeor formula. Cut, maintain, bulk targets.
Open →Maintenance Calorie Calculator
Daily calories to stay the same weight. Mifflin-St Jeor + activity multiplier + 14-day calibration protocol.
Open →Calorie Deficit Calculator
Daily intake target for fat loss with realistic timeline. Goal-rate by % body weight/week + adaptation projection.
Open →Calories Burned Calculator
60+ activities (running, cycling, swimming, gym, sports, yoga) with Ainsworth 2011 Compendium MET values + EPOC.
Open →Macro Calculator
Daily protein, carbs, and fat from any calorie target. Cut / maintain / bulk presets + keto, high-protein, Mediterranean, vegan.
Open →BMR Calculator
Basal Metabolic Rate with three formulas compared: Mifflin-St Jeor, Harris-Benedict, Katch-McArdle.
Open →Protein Calculator
Daily protein target backed by Morton 2018, Helms 2014, and Phillips 2009. Includes per-meal leucine thresholds.
Open →Water Intake Calculator
Personalised hydration target by weight, activity, climate, and pregnancy. Plus the science behind the 8x8 myth.
Open →Weight Loss Timeline
Realistic weeks to your goal — adjusted for metabolic adaptation. Smarter than the naive 3,500 kcal/lb rule.
Open →Body composition
BMI Calculator
Body Mass Index with WHO categories + Asia-Pacific cutoffs. Plus an honest look at when BMI lies.
Open →Body Fat % Calculator
Body fat percentage via the US Navy tape method — accurate to ±3-4% vs DEXA when measured correctly.
Open →Ideal Weight Calculator
Five clinical formulas (Devine, Robinson, Miller, Hamwi, BMI 22) compared. See why they disagree by 5-15 lbs.
Open →Waist-to-Hip Ratio
WHR with WHO 2008 cardiovascular risk thresholds. INTERHEART 2005 + EPIC-Norfolk 2012 evidence summarised.
Open →Waist-to-Height Ratio
"Waist less than half your height" — NICE 2022 + Ashwell 2012 cutoffs. Often outperforms BMI for cardiometabolic risk.
Open →Lean Body Mass
Boer 1984, James 1976, Hume 1966 formulas compared. For protein targets and Katch-McArdle BMR.
Open →Diabetes & glucose
A1C ↔ eAG Converter
HbA1c to estimated Average Glucose in mg/dL and mmol/L. Nathan 2008 ADAG formula + ADA 2024 targets.
Open →Glucose Unit Converter
mg/dL ↔ mmol/L instant conversion. ADA reference ranges for fasting, post-prandial, and hypoglycemia.
Open →Glycemic Load Calculator
GL from GI and carbs per serving. 40+ preset foods using 2021 International Tables. Low/medium/high classification.
Open →Net Carbs Calculator
Net carbs the evidence-based way — full fiber, 100% erythritol/allulose, 50% other sugar alcohols. For keto and T1D dosing.
Open →HOMA-IR Calculator
Insulin resistance from fasting glucose + fasting insulin. Matthews 1985 formula + Bonora 2003 clinical thresholds.
Open →A1C from Avg Glucose
Estimate HbA1c from CGM or fingerstick averages. Nathan ADAG formula, GMI comparison, IFCC mmol/mol output.
Open →Fiber Intake Calculator
Daily fiber target by IOM "14g/1000 kcal" rule + goal modifier (weight loss, glucose, gut). Soluble:insoluble split.
Open →Cardio risk
Diet patterns
Training
Heart Rate Zones Calculator
Five training zones via Standard, Tanaka, or Karvonen formulas. Plus the elite 80/20 polarised training rule.
Open →VO₂ Max Calculator
4 field tests — Cooper, 1.5-mile, Rockport, RHR — with ACSM 2018 age/sex percentile categories.
Open →One-Rep Max Calculator
Five formulas compared — Epley, Brzycki, Lombardi, Lander, O'Conner. Plus % tables for 5/3/1, Sheiko, Starting Strength.
Open →Walking Pace Calculator
Pace × time × distance solver + Cooper test + Tudor-Locke 100 steps/min moderate-intensity threshold.
Open →Steps to Calories
Convert daily steps to calories via MET + weight + stride. Plus Lee 2019 JAMA mortality-benefit plateau.
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