Are my health numbers uploaded to a server?

No. HealthTools is 100% client-side. Every calculation — BMI, BMR, body fat, ovulation — runs in your browser as plain JavaScript. There is no backend and no /api route. The Content-Security-Policy (connect-src 'self') even restricts which hosts the page may contact, so the privacy guarantee is enforced by the browser itself.

Are these calculations accurate?

Each calculator uses a standard, published method for its problem — the WHO BMI bands, the Mifflin-St Jeor equation, the US Navy body-fat method, Naegele's rule for the due date, and so on. A verify suite hand-checks reference values against the implemented math before every build. Still, these are educational estimates, not medical advice; consult a qualified professional for any health decision.

Why does the BMI calculator show two classifications?

People of Asian descent face metabolic risk at a lower BMI, so the WHO recommends Asian-Pacific cutoffs (≥23 overweight, ≥25 obese) alongside the standard Western bands (≥25 overweight, ≥30 obese). We show both so you can compare, which is especially relevant for a Hong Kong audience.

Where do the Cantonese food calories come from?

The food calorie database is a curated, build-time static snapshot bundled same-origin in the repo — it never makes a runtime request to any server. Values are approximate, drawn from public nutrition references, and you can refine them over time. Use them as a guide to portion sizes, not an exact count.

Does it work offline?

Yes. After the first load the app shell is cached, so every calculator works with no internet connection. Install HealthTools as a PWA and it opens and runs offline.

Body Composition

Ideal Weight Calculator

Healthy weight range from the Devine formula, with Robinson, Miller, and Hamwi for comparison.

Ideal Weight Calculator

Healthy weight estimates from your height — Devine plus three comparison formulae.

SexHeight

Your health numbers never leave your device — all math runs in your browser.

Result

Ideal weight (Devine)

56.9 kg

~57.7 kg across all four formulae

Devine (1974)56.9 kg

Robinson (1983)57.4 kg

Miller (1983)59.8 kg

Hamwi (1964)56.4 kg

These formulae give point estimates from height only; they ignore frame size, muscle mass, and age. Treat the spread, not any single number, as your guide.

Height-based formulae (Devine, Robinson, Miller, Hamwi). A rough guide — a healthy weight range is wider than any one estimate. Educational estimate only — not medical advice. See a qualified professional for decisions about your health.

Printable PDF report, saved profiles & meal-plan compare are Pro features.

One-time unlock, no subscription. Unlock HealthTools Pro →

How to use this calculator

Choose your sex.
Enter your height in centimetres.
Read your ideal weight from Devine plus three comparison formulae.

Bookmark Ideal Weight Calculator — it works offline once loaded. Educational estimate only — not medical advice. See a qualified professional for decisions about your health.