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
420 Kilograms to Pounds — Conversion & UK Health Context
420 kilograms equals 925.93 pounds. If you're looking at this weight in a UK health context, it's also equivalent to 66 stone 1.93 pounds. This is a significant weight that falls into the severely obese category according to NHS guidelines. Understanding your weight in different units—kilograms, pounds, and stone—is the first step toward managing your health. Use our free weight converter to switch between these measurements instantly, and check your BMI using our health calculator to understand where you stand relative to NHS healthy weight recommendations.
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.
420kg in UK Health Context — What the NHS Says
At 420 kilograms (925.93 pounds or 66 stone), this weight reflects a health situation that requires professional NHS guidance. According to NHS guidance, any BMI above 40 is classified as severely obese, carrying significant health risks including type 2 diabetes, cardiovascular disease, and obstructive sleep apnoea. The exact health implications depend on your height—for example, at an average UK male height of 5ft 9in (175cm), 420kg would give a BMI of approximately 153, well above the obese threshold. BMI is a useful screening tool, though it has limitations: it doesn't distinguish between muscle and fat or account for where weight is distributed. The NHS recommends that anyone at this weight category consult their GP urgently for a personalised health assessment.
Your GP can assess weight-related health conditions, discuss lifestyle changes, and if appropriate, refer you to specialist tier 3 or tier 4 weight management services available through the NHS.
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.
Taking Action: Tools, Support & Next Steps
If you weigh 420kg, the next step is booking an appointment with your GP. They can assess your individual health, run appropriate tests, and discuss weight management options tailored to you. Many NHS areas now offer specialist weight management services, including structured programmes, dietary support, and in some cases, access to prescription weight loss medication following clinical assessment.
Use our free BMI calculator above to determine your personal BMI based on your height—this gives your GP important context. Track changes over time using our progress tracker. Support is available, and even modest weight loss of 5–10% can meaningfully improve health outcomes including blood pressure, blood sugar control, and mobility.
- 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 many pounds is 420 kilograms exactly?
420 kilograms equals 925.93 pounds. The conversion uses the standard formula: kg × 2.20462 = pounds. Our free weight converter on this page lets you switch between kilograms, pounds, and stone instantly for any weight.
What is 420kg in UK stone and pounds?
420kg equals 66 stone and 1.93 pounds (often written as 66st 1.93lbs). In UK health conversations, stone is the traditional measurement. Our weight converter above handles all three unit systems—kg, stone, and pounds—for easy reference.
What does a BMI mean at 420 kilograms?
BMI depends on your height. The taller you are, the lower your BMI at any given weight. Use our free BMI calculator above (enter your height and 420kg) to find your personal BMI. Any result above 40 is classified as severely obese by NHS guidelines and warrants GP consultation.
Is 420kg a weight that needs medical attention?
Yes. At 420kg, NHS guidance strongly recommends consulting your GP. This weight category is associated with significant health risks and qualifies for specialist NHS weight management services. Your GP can assess your individual situation and discuss appropriate support options.
What weight loss rate is safe if I weigh 420kg?
The NHS recommends losing 0.5–1kg per week for sustainable results. At 420kg, weight loss should be managed with professional NHS support. Your GP or specialist weight management team can create a safe plan tailored to your health, lifestyle, and goals.
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.