For the complete documentation index, see llms.txt.
26 endpoints

Health API

Same bearer token, same credit pool, same JSON envelope as every other endpoint — drop them into apps, sites, workflows, or agents without rebuilding formulas, validation, or docs.

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Body Metrics
BMI Calculatorbmi-calculator
Calculate Body Mass Index, BMI Prime, and healthy weight range in metric or imperial units.
1cr · v2026-04-22
Body Fat Percentage Calculatorbody-fat-percentage-calculator
Estimate body fat percentage with the US Navy method and age-adjusted healthy ranges.
1cr · v2026-04-22
Body Surface Area Calculatorbody-surface-area-calculator
Estimate body surface area using Mosteller, Du Bois, or Haycock formulas.
1cr · v2026-04-22
Child Height Predictorchild-height-predictor
Predicted adult height from parents' heights via the mid-parental (Tanner) method with range and adult percentile.
1cr · v2026-04-22
Ideal Weight Calculatorideal-weight-calculator
Ideal body weight via Devine, Robinson, Miller, and Hamwi formulas with frame-size adjustment and healthy BMI range.
1cr · v2026-04-22
Lean Body Mass Calculatorlean-body-mass-calculator
Lean body mass via Boer, James, and Hume equations with estimated body fat percentage and category.
1cr · v2026-04-22
Waist to Hip Ratio Calculatorwaist-to-hip-ratio-calculator
Waist-to-hip ratio with WHO risk category, body shape pattern, and the waist target for a healthy ratio.
1cr · v2026-04-22
Diabetes
Blood Sugar Converterblood-sugar-converter
Convert blood glucose between mg/dL and mmol/L with fasting-range category and reference table.
1cr · v2026-04-22
HbA1c Calculatorhba1c-calculator
Convert between HbA1c percentage and estimated average glucose (mg/dL and mmol/L) with ADA interpretation.
1cr · v2026-04-22
Fitness
Heart Rate Zone Calculatorheart-rate-zone-calculator
Estimate heart-rate training zones using max-heart-rate or Karvonen formulas.
1cr · v2026-04-22
Max Heart Rate Calculatormax-heart-rate-calculator
Maximum heart rate from six validated formulas (Fox, Tanaka, Gellish, Gulati, Nes, Arena) with training zones.
1cr · v2026-04-22
One Rep Max (1RM) Calculatorone-rep-max-calculator
One-rep max estimated by seven formulas (Brzycki, Epley, Lander, Lombardi, Mayhew, O'Conner, Wathan) with training zones and warm-up sets.
1cr · v2026-04-22
Steps to Distance Calculatorsteps-to-distance-calculator
Estimate distance walked or run from a step count and height.
1cr · v2026-04-22
Hydration
Water Intake Calculatorwater-intake-calculator
Estimate daily water intake from body weight, activity, and hot-weather adjustment.
1cr · v2026-04-22
Kidney Function
Creatinine Clearance Calculatorcreatinine-clearance-calculator
Estimate creatinine clearance with the Cockcroft-Gault equation and CKD stage.
1cr · v2026-04-22
FENa Calculatorfena-calculator
Fractional excretion of sodium (FENa) with prerenal / indeterminate / intrinsic-renal interpretation.
1cr · v2026-04-22
GFR Calculatorgfr-calculator
Estimated GFR via CKD-EPI 2021 (primary), CKD-EPI 2009, MDRD, and Cockcroft-Gault with CKD staging.
1cr · v2026-04-22
Lab Values
ANC Calculatoranc-calculator
Absolute neutrophil count from CBC values with NCI CTCAE neutropenia grading.
1cr · v2026-04-22
BUN to Creatinine Ratio Calculatorbun-to-creatinine-ratio-calculator
Calculate the BUN to creatinine ratio with unit conversion and reference range.
1cr · v2026-04-22
Corrected Calcium Calculatorcorrected-calcium-calculator
Albumin-corrected calcium (Payne 0.8 or modified 0.6 coefficient) with clinical interpretation.
1cr · v2026-04-22
Corrected Sodium Calculatorcorrected-sodium-calculator
Hyperglycemia-corrected sodium via Katz and Hillier formulas with severity interpretation.
1cr · v2026-04-22
Nutrition
Caffeine Limit Calculatorcaffeine-overdose-calculator
Estimate a safe daily caffeine limit and what it equals in drinks.
1cr · v2026-04-22
Calorie Deficit Calculatorcalorie-deficit-calculator
Estimate daily calorie deficit, target intake, and projected weight-loss trend.
1cr · v2026-04-22
Protein Intake Calculatorprotein-intake-calculator
Estimate daily protein intake and per-meal targets from weight and training goal.
1cr · v2026-04-22
Pregnancy
Due Date Calculatordue-date-calculator
Pregnancy due date via Naegele's rule from LMP, conception date, or ultrasound, with trimester milestones.
1cr · v2026-04-22
Gestational Age Calculatorgestational-age-calculator
Work out gestational age in weeks and days plus the estimated due date.
1cr · v2026-04-22