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
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120 Kg In Stones And Pounds — What's Your BMI?
120 kg converts to 18 stone 12 pounds (or 18st 12lbs) using the standard kilogram to stone conversion. However, your BMI at this weight depends entirely on your height. The same weight can fall into different NHS categories depending on how tall you are. Use our free BMI calculator above to find your exact BMI, or read below to see where 120 kg sits across common UK heights.
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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.
BMI At 120 Kg Across Different Heights
At 120 kg, your BMI varies significantly based on height. Here's how this weight converts across common heights:
- 5ft 4in (163 cm): BMI = 39.9 — Obese (Class II)
- 5ft 6in (168 cm): BMI = 37.7 — Obese (Class II)
- 5ft 8in (173 cm): BMI = 35.9 — Obese (Class II)
- 5ft 10in (178 cm): BMI = 34.1 — Obese (Class I)
- 6ft 0in (183 cm): BMI = 32.0 — Obese (Class I)
- 6ft 2in (188 cm): BMI = 30.1 — Obese (Class I)
As you can see, 120 kg falls into the obese category (BMI 30 or above) across all typical adult heights. The higher you are, the lower your BMI at this weight, but it remains in the obese range. Converting weight to stone and pounds shows this is approximately 18st 12lbs, a useful reference point for UK health discussions with your GP.
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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.
NHS BMI Categories And What They Mean
The NHS uses BMI categories to assess health risk, not to judge individuals. At 120 kg, most adults fall into the Obese Class I or II category, which means there may be increased health risks including type 2 diabetes, heart disease, and high blood pressure. However, BMI has limitations — it doesn't account for muscle mass, where fat is stored, or overall fitness. Your GP can provide personalised advice about your weight and health. For adults of South Asian, Chinese, Black African, or Caribbean heritage, the NHS recommends lower BMI thresholds, meaning eligibility for support may differ. Even a modest 5–clinically studied weight loss can significantly improve health markers.
- 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.
How do I convert 120 kg to stone and pounds?
Divide 120 kg by 6.35029 to get stone. 120 ÷ 6.35029 = 18.9 stone. This equals 18 stone and 12.6 pounds (often rounded to 18st 12lbs). You can use our free weight converter to switch instantly between kg, stone, and pounds for any weight.
Is 120 kg overweight or obese according to the NHS?
At 120 kg, your BMI category depends on your height. For most adult heights, 120 kg falls into the Obese Class I or II range (BMI 30+). Use our free BMI calculator above to check your exact BMI and NHS category based on your specific height.
What's a healthy weight if I'm 120 kg right now?
A healthy weight range depends on your height. For example, at 5ft 8in (173 cm), a healthy BMI (18.5–24.9) corresponds to roughly 55–74 kg. Your GP can advise on a realistic and healthy target weight for your circumstances.
Can I lose weight safely from 120 kg?
Yes. The NHS recommends losing 0.5–1 kg per week for sustainable results. This typically requires a calorie deficit of around 500 kcal per day. Combining dietary changes with increased physical activity works best. Your GP can discuss a personalised plan and whether you might benefit from additional support like prescription weight management.
Does 120 kg mean I'm eligible for weight loss medication in the UK?
Possibly. At 120 kg, you may be eligible for prescription weight management medication if your BMI is 30+ or 27+ with weight-related health conditions. Eligibility is assessed individually by a GP or specialist. Try our GLP-1 weight loss calculator to explore potential options, then discuss with your healthcare provider.
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.