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 Does 100kg Mean for Your Health in the UK?
100kg is approximately 15 stone 10 pounds in UK measurements. Understanding what this weight means for your health requires looking at your BMI, height, and overall health context rather than the number alone. The NHS approach to healthy weight focuses on individual circumstances, not just a single figure. This guide explains where 100kg sits in relation to NHS health guidance, helps you convert to familiar UK units, and shows you what tools and resources are available to assess your personal health picture.
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.
100kg and NHS Health Context
At 100kg, whether your health is at a healthy level depends entirely on your height and individual circumstances. The NHS uses BMI (body mass index) as a screening tool to assess health risk, not to judge anyone. For example, a 100kg adult who is 1.88m (6ft 2in) tall would have a BMI of approximately 28.3, which falls in the overweight category but is relatively modest for their height. However, a 100kg adult who is 1.60m (5ft 3in) tall would have a BMI of approximately 39, which sits in the obese category and may warrant health discussion with a GP.
- BMI 18.5–24.9: Healthy weight range (NHS guidance)
- BMI 25–29.9: Overweight range
- BMI 30+: Obese range (increased health risk)
The NHS recommends that rather than focusing on a specific weight, you consider your waist measurement, overall fitness level, and any weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea). Use our free BMI calculator above to check your personal BMI — it only takes your height and weight.
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.
UK Tools and Next Steps
If you're at 100kg and wondering whether your weight is healthy for your body, the best starting point is speaking with your GP, who can assess your individual risk factors. Your GP may refer you to NHS weight management services if appropriate — these are free and available through your local integrated care board.
For practical next steps: convert your weight to stone and pounds using our free weight converter to see it in familiar UK units, calculate your BMI using the calculator on this page to understand where you sit, and if you're interested in weight loss support, our GLP-1 weight loss calculator can help you understand potential approaches. The NHS Weight Loss Plan is also available free online as a starting point for lifestyle changes.
- 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 100kg overweight or obese?
It depends on your height. BMI = weight in kg ÷ height in metres squared. At 100kg, if you're average UK height (around 1.70m), your BMI would be approximately 34.5, which falls in the obese category. However, if you're taller, it may be overweight or even healthy. Use our BMI calculator above to check your specific BMI.
What is 100kg in stone and pounds?
100kg converts to approximately 15 stone 10 pounds (or 220.5 pounds). You can use our free weight converter on this page to convert between kg, stone, and pounds instantly.
Should I lose weight if I'm 100kg?
Only your GP can advise on whether weight loss is right for you personally. The NHS recommends discussing weight with your GP if you have health conditions related to weight, such as type 2 diabetes, high blood pressure, or joint pain. Even a 5–clinically studied weight loss can improve health outcomes.
What healthy weight range should I aim for at my height?
Your healthy weight range depends on your height. A healthy BMI is 18.5–24.9. For example, if you're 1.75m tall, your healthy weight range is approximately 56–76kg. Use our BMI calculator to find your personalised healthy weight range in seconds.
Where can I get NHS weight management support?
Your GP can refer you to tier 3 NHS specialist weight management services, which are free and available in most areas (though waiting lists vary). Alternatively, the NHS Weight Loss Plan is free online. Your GP can also discuss whether prescription weight loss support might be suitable for you.
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.