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
6.8 Pounds in Kg — What's Your BMI?
6.8 pounds converts to approximately 3.09 kg — a relatively light weight that typically corresponds to a very low BMI across most adult heights. Your BMI at this weight depends entirely on your height, which is why the same weight in kilograms produces very different health classifications for different people. Use our free BMI calculator above to enter your exact height and see your personal BMI instantly, or scroll down to see example BMI values at common heights using this weight.
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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.
BMI at 6.8 Pounds (3.09 kg) — Examples by Height
At 6.8 pounds (3.09 kg), your BMI will vary significantly depending on your height. Here are typical examples using this weight to illustrate the relationship between weight, height, and BMI:
- At 160 cm (5ft 3in): BMI = 12.0 — underweight (NHS healthy range is 18.5–24.9)
- At 170 cm (5ft 7in): BMI = 10.7 — underweight
- At 175 cm (5ft 9in): BMI = 10.1 — underweight
- At 180 cm (5ft 11in): BMI = 9.5 — underweight
- At 190 cm (6ft 3in): BMI = 8.5 — underweight
At this very low weight, your BMI falls well below the NHS healthy weight threshold regardless of height. This weight is extremely light for an adult and may indicate significant underweight status. If you're at or near this weight and concerned about your health, speaking with your GP is important to rule out underlying conditions or nutritional issues.
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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 BMI Categories and Health Context
The NHS defines a healthy BMI as 18.5 to 24.9 for most UK adults. A BMI below 18.5 is classified as underweight, which can be associated with health concerns including weak immune function, bone health issues, and nutritional deficiencies. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, slightly different thresholds apply due to higher health risks at lower BMI levels. Remember that BMI has limitations — it doesn't account for muscle mass, bone density, or where fat is stored. For personalised weight health guidance, your GP can provide context specific to your individual health history and 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 6.8 pounds to kg exactly?
6.8 pounds = 3.086 kg (often rounded to 3.09 kg). The conversion formula is pounds × 0.453592 = kg. Our free weight converter above lets you switch between pounds, kilograms, stone, and other units instantly.
What does a BMI of around 10 mean for health?
A BMI of 10 is significantly underweight according to NHS guidelines. Underweight status can indicate nutritional deficiency, weak immune function, or underlying health conditions. If you're at this weight, consulting your GP is advisable to ensure your health is being properly supported.
Why does the same weight give different BMI values at different heights?
BMI is calculated as weight (kg) divided by height (metres) squared. Because height is squared in the formula, taller people have lower BMI values at the same weight. This is why BMI is height-dependent — it's designed to account for how body composition changes as you get taller.
Is 6.8 pounds a realistic adult body weight?
6.8 pounds (3.09 kg) is extremely light for an adult human. This weight is typical for a newborn baby, not an adult. If you're looking to understand your own weight, try our free BMI calculator with your actual body weight and height to get meaningful health context.
Can I use the kg to stone conversion to understand my weight better?
Yes. 3.09 kg converts to approximately 0.49 stone (or about 6.8 pounds). Many UK adults find it easier to think about weight in stone and pounds rather than metric. Our weight converter supports all common units for easy comparison.
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.