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
17.2 Lb to Kg — Is This a Healthy Weight for You?
17.2 pounds equals approximately 7.8 kilograms. Whether this is a healthy weight depends entirely on your height — there's no one-size-fits-all answer. A weight that's healthy for one person might be overweight for another, or underweight for a third. The NHS uses BMI (body mass index) as the main screening tool to assess whether a weight is healthy for your individual height. Use our free BMI calculator above to check your personal BMI instantly and see where your weight falls on the NHS health scale.
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.
Healthy Weight Ranges by Height
At 7.8 kg (17.2 lb), you would need to be quite short for this to fall within a healthy weight range. Here are three concrete examples showing how the same weight can be healthy, overweight, or severely underweight depending on height:
- At 100 cm (3ft 3in): BMI = 7.8, which is severely underweight — requiring medical attention
- At 120 cm (3ft 11in): BMI = 5.4, also severely underweight — this would typically be a young child, not an adult
- At 140 cm (4ft 7in): BMI = 3.9, severely underweight — well below the healthy range of 18.5–24.9
For context, 7.8 kg is an extremely low weight for any adult. Most UK adults weigh significantly more. Use the weight converter tool on this page to explore healthy weight ranges for your actual height, or calculate your personal BMI using our free calculator.
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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 Guidance for Your Healthy Weight
According to NHS guidelines, a healthy BMI is between 18.5 and 24.9 for most UK adults. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends slightly lower thresholds (18.5–22.9). If your weight falls outside these ranges, your GP can offer support and guidance tailored to your individual health.
Waist measurement also matters. Even if your BMI is in the healthy range, where you carry fat is important — excess weight around the stomach increases health risks. Healthy waist measurements are under 94 cm (37 inches) for men and under 80 cm (31.5 inches) for women. If you're concerned about your weight or health, talk to your GP who can assess your complete health picture.
- 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 17.2 lb converted to kilograms?
17.2 pounds equals approximately 7.8 kilograms. To convert pounds to kg, divide the pound value by 2.20462. This is a very low weight for any adult and would only fall in a healthy range for a young child, not an adult.
How do I know if a weight is healthy for me?
Calculate your BMI using your weight and height. The NHS considers a BMI of 18.5–24.9 healthy for most adults (18.5–22.9 for South Asian and other specified ethnicities). Use our free BMI calculator on this page to check your personal BMI instantly based on your actual height and weight.
Is waist measurement as important as weight?
Yes. The NHS recommends measuring waist circumference alongside weight, as where fat is stored matters for health risks. A healthy waist is under 94 cm (37 inches) for men and under 80 cm (31.5 inches) for women, regardless of overall weight.
What should I do if my weight is outside the healthy range?
Speak to your GP. They can assess your individual health, discuss any underlying health conditions, and recommend evidence-based support — whether that's lifestyle changes, behaviour support programmes, or other options. The NHS also offers free weight management resources and calculators online.
How do I convert between stone, pounds, and kilograms?
Use a metric to imperial weight conversion calculator for accuracy. As a quick guide: 1 stone = 6.35 kg, 1 kg = 2.20462 lbs. Our weight converter tool on this page handles all conversions instantly — just enter your weight in any unit.
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.