Scientific Integrity
Every formula we use is traceable to a published, peer-reviewed source. We cite our methodology. We don't round numbers to make results look better.
WellCal exists so that anyone — regardless of background or budget — can access clear, science-backed health information. No paywalls. No sign-ups. Just honest numbers that help you make better decisions about your body.
WellCal was built on a straightforward premise: you deserve to understand your own health metrics without needing a medical degree, a gym membership, or a subscription fee. Millions of people Google health questions every day — and too often land on confusing jargon, premium paywalls, or tools that harvest their data.
We built WellCal to be the opposite. Every calculator on this platform — from BMI to water intake to sleep needs — uses validated, peer-reviewed methodology and presents results in plain, actionable language. We don't simplify the science; we translate it.
Our calculators reference guidance from the World Health Organisation (WHO), the Centers for Disease Control (CDC), the National Institutes of Health (NIH), and Mayo Clinic. When the science says something, we say it too — clearly, honestly, and without sensationalism.
These aren't marketing words — they're the real decisions we make every time we build, update, or review a calculator on this platform.
WellCal started with a frustration most of us have shared: opening ten tabs to answer one simple health question and still not getting a straight answer. The existing tools were either buried behind paywalls, cluttered with ads, or using opaque formulas that produced results you couldn't interpret or trust.
We believed the problem wasn't demand — millions of people search for "how much water should I drink" or "what's a healthy BMI" every single day. The problem was supply. The tools that existed weren't built around the user's needs; they were built around monetisation.
WellCal was built the other way around. We started with the question: "What would the most useful, most trustworthy free health tool look like?" — and built backward from there. Every design decision, every formula choice, every piece of content exists to serve that question.
It's not just what we calculate — it's how carefully we do it, and what we refuse to do in the process.
Every WellCal calculator uses the specific, published formula recommended by a leading health authority — not a generic approximation. Our BMI calculator, for example, uses the exact WHO formula (kg/m²) with WHO-defined classification thresholds, not a simplified rounding. Our calorie calculator uses the Mifflin-St Jeor equation, the same formula used in clinical dietetics. The formula you use matters.
Most calculators give you a number and leave. WellCal explains what that number means, what the healthy range is, what factors affect it, and what to do if your result is outside the normal range. When you check your cholesterol ratio or diabetes risk score, you leave with context — not just a figure.
Nothing you enter into a WellCal calculator is transmitted to our servers. All computations are performed client-side in your browser. We don't set tracking cookies on calculator pages. We don't ask you to create an account. Your hydration data, your macro splits, your pregnancy dates — all private, always.
Every calculator page on WellCal is accompanied by real educational content: what the metric is, how it's measured, what affects it, and how to interpret your result. Our editorial team writes for health-aware adults, not for an algorithm. We cite every authority we reference and link to the source. What you read on WellCal is accurate or we don't publish it.
WellCal is built to WCAG 2.1 accessibility guidelines. All calculators work on any device. Inputs are clearly labelled with semantic HTML. Results are communicated through text as well as any visual indicator. We don't design for a specific type of user — we design for all users.
All tools are free, require no account, and are regularly reviewed against current clinical guidance from the WHO, CDC, NIH, and Mayo Clinic.
We made these commitments when we launched, and we honour them with every page, calculator, and update we ship.
We take our responsibility to publish accurate, trustworthy health content seriously. Please read this section carefully.
WellCal is a small, focused team — which means when you email us, a real person reads it. We welcome feedback on calculator accuracy, requests for new tools, corrections to our content, and partnership enquiries.
If you think we've got a formula wrong, a reference outdated, or a result that doesn't seem right — please tell us. Getting the science right matters more to us than any other metric.
Start with any of WellCal's free health calculators — no account, no cost, and no data stored. Just clear, science-backed answers about your body.