Health Calculator Guides
Articles that explain formulas, edge cases, and interpretation for health calculators. Each guide links to the relevant tools so you can apply what you learn.
Understanding BMI: Ratio, WHO Band Rail, Weight Corridor, Same-BMI Frames
BMI is weight ÷ height², a screening ratio, not a health diagnosis. Walk the formula, WHO adult bands, the 18.5–24.9 weight corridor for your height, same-BMI different-body frames, and optional Asian overlay context. Educational only.
BMI Inputs Done Right: Height, Weight, and Unit Traps
Get adult BMI right before you interpret it. A measurement protocol for height and weight, unit traps that flip categories, and worked examples of how small input errors move the band.
Weekly Pace, Daily Calories, and the BMR Floor
Plan weight change as a weekly pace, map it to a daily calorie target from maintenance, and check the BMR floor before you crash. Worked budgets, activity honesty, and when to hand off to TDEE or macros.
Backdating Conception: LMP, Due Date, and the Look-Back Band
Estimate conception by working backward from LMP or a due date, peel the luteal assumption, and read a look-back fertile band. Educational timing literacy, not contraception or a diagnosis.
Resting Heart Rate: Count Window to BPM, Multi-Sample Average, Consistency Peel
A single short pulse count can lie. Convert 15/30/60-second windows to BPM, average a morning trio, and read spread before you trust the band. Verified steady vs noisy twins with an educational adult rail. Not a diagnosis or ECG.
After Your BMI Number: A Calm Next-Step Health Stack
Treat adult BMI as a screening map, not a verdict. Build a next-step stack with waist context, energy and habits, related calculators, and clear rules for when to talk to a clinician.
Intermittent Fasting Schedules: Protocol Ladder and Window Placement
Build a 14:10 to 20:4 fasting split on a 24-hour clock. See why the same 16:8 protocol changes with start time, and why an eating window is logistics, not an automatic calorie deficit.
Protein Targets: Scale Weight vs Base Mass, and a g/kg Ladder
Protein is g/kg × mass, but which mass? Compare current vs goal weight at the same intensity, climb an RDA-to-cut ladder, and hand off to macros for the rest of the plate. Educational bands, not prescriptions.
One-Rep Max Estimates: Submax Sets, Formula Twins, and %1RM Loads
Turn a hard submax set into an estimated 1RM with Epley and Brzycki, read the formula delta as noise, then build a %1RM intensity ladder for working weights. Estimates are programming tools, not tested gym ceilings.