The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
Free tracker included with every download this week
What Do BMI 28 and BMI 2 Mean for UK Adults?
BMI is a simple health screening tool that uses your weight and height to estimate whether you're at a healthy weight for your age and sex. A BMI of 28 falls into the overweight category according to NHS guidelines, while a BMI of 2 is extremely low and would require urgent medical attention. This guide explains what these numbers mean, how they're calculated, and what NHS guidance recommends for your health. Use our free BMI calculator above to find your own BMI instantly and understand where you sit on the NHS health spectrum.
10,000+ calculations today · NHS-aligned thresholds · 100% free
Calculate Your BMI Instantly
Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
NHS BMI Categories and What They Mean for Your Health
The NHS defines BMI categories to help adults understand their weight status and associated health risks. A BMI of 28 places you in the overweight category (BMI 25–29.9), which the NHS indicates carries increased health risk compared to a healthy weight. A BMI of 2, by contrast, is dangerously low and would indicate severe malnutrition or an extreme medical emergency requiring immediate GP intervention.
- Healthy weight (BMI 18.5–24.9): Lowest health risk for most adults
- Overweight (BMI 25–29.9): Increased risk of type 2 diabetes, high blood pressure, and heart disease
- Obese (BMI 30–34.9): Substantially elevated health risks
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds — overweight starts at BMI 23 for these groups due to higher cardiovascular risk at lower BMI levels. Your GP can discuss what a healthy weight range means specifically for you.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
What You Can Do If Your BMI Is 28 — NHS-Recommended Steps
If your BMI is 28, the NHS recommends starting with lifestyle changes: aim for a calorie deficit of around 500 kcal per day to lose approximately 0.5 kg per week. This means reducing portion sizes, choosing lower-calorie foods, and increasing physical activity to at least 150 minutes of moderate exercise weekly. The NHS Weight Loss Plan (available free through your GP) provides step-by-step support, meal ideas, and a progress tracker.
If you've tried lifestyle changes without success, your GP may refer you to a specialist tier 3 weight management service, where prescription weight loss medications may be considered. Use our free weight converter and progress tracker to monitor your weight in stone, kg, or lbs — whichever unit feels most natural to you.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Is a BMI of 28 considered overweight in the UK?
Yes. According to NHS guidance, BMI 25–29.9 is classified as overweight. A BMI of 28 means you're at increased risk of type 2 diabetes, heart disease, and high blood pressure compared to a healthy BMI (18.5–24.9). Your GP can advise on whether weight loss would benefit your personal health.
What does a BMI of 2 mean?
A BMI of 2 is critically low and indicates severe malnutrition or extreme weight loss. This would be a medical emergency requiring immediate hospital assessment. If you or someone you know has a BMI this low, please seek urgent medical help from your GP or A&E.
How can I calculate my own BMI?
Use our free BMI calculator on this page — simply enter your weight in kg (or stone and pounds) and your height in cm (or feet and inches), and the calculator shows your BMI instantly. You can also calculate manually: BMI = weight (kg) ÷ height (m)².
Should I try to lose weight if my BMI is 28?
If your BMI is 28, the NHS recommends discussing weight management with your GP. Even a 5–10% reduction in body weight can reduce health risks. Your GP can assess whether weight loss is right for you based on your overall health, family history, and any existing health conditions.
Can BMI limitations affect how I understand my health?
Yes. BMI doesn't distinguish between muscle and fat — athletes may have a high BMI but low body fat. BMI also doesn't account for where fat is stored; waist circumference matters too. For adults over 65, BMI is less reliable. Always discuss your results with your GP for personalised health advice.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.