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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12.7 Kg To Pounds — Health Context
12.7 kg converts to approximately 28 pounds. Whether this weight is healthy for you depends entirely on your height — the same weight can be perfectly healthy for one person and underweight for another. The NHS uses BMI (Body Mass Index) to assess whether a weight falls within a healthy range, and this takes both weight and height into account. Use our free BMI calculator above to check your personal BMI instantly and see where your weight sits according to UK health guidelines.
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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.
Healthy Weight Ranges at Different Heights
At 12.7 kg (28 lbs), you're looking at a very light weight, which would typically only fall within a healthy range for very young children or specific medical contexts. For adults, here are three examples showing how the same weight relates to health across different heights:
- At 150 cm (4ft 11in): 12.7 kg gives a BMI of 5.7 — this is significantly underweight and would require medical assessment
- At 160 cm (5ft 3in): 12.7 kg gives a BMI of 4.9 — this is severely underweight and indicates a serious health concern
- At 170 cm (5ft 7in): 12.7 kg gives a BMI of 4.4 — this is critically underweight and would require urgent medical attention
These examples illustrate why height matters so much. If you're an adult at 12.7 kg, this would fall well below the healthy weight range for any typical adult height. The NHS recommends a BMI between 18.5 and 24.9 for most adults — to find your healthy weight range at your height, convert your measurements using metric to imperial weight calculations or use our weight converter to compare different units.
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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.
What To Do If Your Weight Is Outside Healthy Range
If you're significantly underweight, the NHS recommends speaking with your GP, as this can indicate nutritional deficiency, underlying health conditions, or other concerns that need professional assessment. Your GP can measure your height accurately, calculate your BMI, and discuss whether your weight is appropriate for your individual circumstances.
Weight in stone and pounds can be helpful for tracking, but the most important thing is understanding your healthy weight range at your specific height. If you're concerned about being underweight, overweight, or unsure what a healthy weight means for you personally, your GP can provide personalised guidance. Non-judgmental support is available through the NHS — weight is complex and affected by many factors including genetics, medical conditions, and life circumstances.
- 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 12.7 kg to stone and pounds?
12.7 kg equals approximately 2 stone exactly (or 2st 0lbs). To convert kilograms to stone, divide by 6.35029. Use our free weight converter on this page to switch instantly between kg, stone, and pounds in any direction.
Is 12.7 kg a healthy weight for an adult?
At 12.7 kg, this would be significantly underweight for any adult height and would require medical assessment. Healthy adult weights vary by height — use our BMI calculator to check if your current weight is within the NHS healthy range for your height.
What is the healthy weight range for my height?
Healthy weight depends on both your weight and height. The NHS recommends a BMI between 18.5 and 24.9. Calculate your personal healthy weight range instantly using our free BMI calculator above, which accounts for your exact height and gives you a personalised healthy weight range.
How is BMI calculated?
BMI = weight (kg) ÷ height (m)². For example, at 170 cm and 70 kg, your BMI would be approximately 24.2 (healthy range). BMI is a useful screening tool but has limitations — it doesn't account for muscle mass or where fat is stored. Your GP can discuss what BMI means for your personal health.
Should I be concerned if my weight is 12.7 kg?
Yes — at 12.7 kg, this is significantly below healthy range for adults and requires medical attention. If this applies to you or someone you know, contact your GP urgently for assessment. They can discuss your individual health situation and any support needed.
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.