Question 1

Are my health numbers uploaded to a server?

Accepted Answer

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.

Question 2

Are these calculations accurate?

Accepted Answer

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.

Question 3

Why does the BMI calculator show two classifications?

Accepted Answer

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.

Question 4

Where do the Cantonese food calories come from?

Accepted Answer

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.

Question 5

Does it work offline?

Accepted Answer

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.

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