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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27.5 Pounds to kg — What's Your BMI?
27.5 pounds converts to approximately 12.5 kg. However, your BMI — the main health indicator — depends entirely on your height. At different heights, 27.5 pounds (12.5 kg) gives very different BMI values and falls into different NHS weight categories. Use our free BMI calculator above to find your exact BMI, or read on to see how this weight compares 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.
27.5 Pounds to kg at Different Heights
27.5 pounds equals 12.5 kg exactly. Here's what this weight means for your BMI at six common heights:
- 5ft 0in (152 cm): BMI 32.8 — Obese (Class I)
- 5ft 4in (163 cm): BMI 28.2 — Overweight
- 5ft 8in (173 cm): BMI 25.2 — Overweight
- 5ft 10in (178 cm): BMI 23.6 — Healthy weight
- 6ft 0in (183 cm): BMI 22.2 — Healthy weight
- 6ft 2in (188 cm): BMI 20.9 — Healthy weight
At shorter heights, this weight falls above the NHS healthy range; at taller heights, it's within the healthy weight zone. Your GP can provide personalised guidance about what this means for your individual health. Try our weight converter to switch between kilograms, stone, and pounds easily.
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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 NHS BMI Categories
The NHS uses five BMI categories for adults:
- Underweight: Below 18.5
- Healthy weight: 18.5 to 24.9
- Overweight: 25.0 to 29.9
- Obese (Class I): 30.0 to 34.9
- Obese (Class II and above): 35.0 or higher
For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds — the healthy range starts at 18.5 and ends at 22.9. Remember, BMI is a screening tool only and doesn't account for muscle mass, where fat is stored, or individual health conditions. Calculate your personal BMI using the tool on this page for context.
- 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 27.5 pounds in kilograms?
27.5 pounds converts to exactly 12.5 kg. To convert pounds to kilograms, divide the pound value by 2.20462. This is the standard conversion for metric to imperial weight measurements used across the UK.
Is 27.5 pounds a healthy weight?
It depends entirely on your height. At 5ft 10in, it's within the healthy BMI range. At 5ft 4in, it falls in the overweight category. At 5ft 0in, it's classified as obese by NHS standards. Use our free BMI calculator above to check your personal BMI.
How do I convert 27.5 pounds to stone and pounds?
27.5 pounds equals 1 stone and 13.5 pounds (approximately 1st 13.5lbs). One stone is exactly 14 pounds, so divide 27.5 by 14 to get stone, then use the remainder for pounds. Use our weight converter for instant conversions.
What's the difference between BMI and ideal weight?
BMI is a health screening measure based on height and weight. Ideal weight is the healthy weight range for your height according to NHS guidelines. Both are useful, but BMI doesn't account for muscle mass or individual factors — your GP can advise what's right for you.
Can BMI be inaccurate?
Yes. BMI doesn't distinguish between muscle and fat, so athletes may have high BMI but low body fat. It also doesn't account for where fat is stored (waist measurement matters too) or age-related changes. It's a screening tool, not a diagnosis.
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.