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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420 Lbs to Kg — What's Your BMI?
420 lbs converts to approximately 190.5 kg. Your BMI at this weight depends entirely on your height — the same weight produces very different health categories for different people. Using our free BMI calculator, you can enter your exact height to see where you fall on the NHS BMI scale. Understanding both your weight in kilograms and your BMI is essential for assessing health risk. This guide shows you how to convert 420 lbs to kg and what your BMI means according to NHS guidelines, with practical examples at common UK heights.
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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.
420 Lbs in Kilograms — BMI at Different Heights
420 lbs = 190.5 kg exactly. This weight produces different BMI results depending on your height. Here are six common UK heights and the corresponding BMI at 420 lbs:
- 5ft 4in (163cm): BMI 34.5 — Obese (Class I)
- 5ft 6in (168cm): BMI 31.9 — Obese (Class I)
- 5ft 8in (173cm): BMI 29.6 — Overweight
- 5ft 10in (178cm): BMI 27.8 — Overweight
- 6ft 0in (183cm): BMI 25.9 — Overweight
- 6ft 2in (188cm): BMI 24.3 — Healthy weight
If you want to convert 420 lbs to stone, that's approximately 30 stone. Use our free weight converter to switch between kg, stone, and pounds instantly for your exact measurements.
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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.
Understanding Your BMI Category — NHS Guidelines
According to NHS guidelines, a healthy BMI is between 18.5 and 24.9 for most UK adults. At 420 lbs (190.5 kg), most adults fall into the overweight or obese range depending on height. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends even lower thresholds because these groups have higher health risks at the same BMI.
BMI is a useful screening tool, but it has limitations — it doesn't distinguish between muscle and fat, and doesn't account for where fat is stored. Waist measurement also matters: men over 94cm (37in) face increased risk, and women over 80cm (31.5in) face increased risk. Try our free BMI calculator above to check your personal category, and speak with your GP for personalised health advice.
- 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.
What is 420 lbs in kg?
420 lbs equals 190.5 kg. To convert, divide pounds by 2.20462. For metric to imperial weight conversions, you can use the reverse: multiply kg by 2.20462 to get pounds. Our free weight converter above handles all unit conversions instantly.
What BMI is 420 lbs?
Your BMI at 420 lbs depends on your height. At 5ft 8in you'd have a BMI of 29.6 (overweight); at 6ft 0in you'd have 25.9 (overweight). Use our BMI calculator to enter your exact height and see your personal BMI category and NHS classification.
Is 420 lbs obese?
At 420 lbs, whether you're classified as obese depends on your height. Shorter adults at this weight fall into obese categories (BMI 30+), whilst taller adults may be in the overweight range. Your GP can provide personalised advice about health risks based on your individual measurements.
How much is 420 lbs in stone?
420 lbs is approximately 30 stone. To convert pounds to stone, divide by 14 (since 1 stone = 14 lbs exactly). You can also use our free weight converter to switch between stone and pounds instantly.
What's a healthy weight for my height?
A healthy weight depends on your height. The NHS BMI range of 18.5–24.9 gives you a healthy weight band. For example, at 5ft 8in, a healthy weight is roughly 55–74 kg (8st 10lbs to 11st 10lbs). Calculate your personal healthy weight range using our free BMI calculator above.
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.