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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77.8 Kilos in Stones and Pounds — What's Your BMI?
77.8 kilograms converts to 12 stone 2 pounds (12st 2lbs) or 171.4 pounds. However, your BMI — which determines whether this weight falls into a healthy range — depends entirely on your height. At different heights, 77.8kg gives very different BMI values and NHS health categories. Use our free BMI calculator above to find your personal BMI, or read on to see how this weight relates to health 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.
77.8kg BMI at Different Heights
To understand whether 77.8kg is a healthy weight for you, you need to calculate your BMI. Here's how 77.8kg converts to BMI at six common heights in the UK:
- At 5ft 2in (157cm): BMI = 31.6 (obese category)
- At 5ft 4in (163cm): BMI = 29.2 (overweight category)
- At 5ft 6in (168cm): BMI = 27.5 (overweight category)
- At 5ft 8in (173cm): BMI = 26.0 (overweight category)
- At 5ft 10in (178cm): BMI = 24.6 (healthy weight range)
- At 6ft 0in (183cm): BMI = 23.2 (healthy weight range)
The NHS defines a healthy BMI as 18.5 to 24.9. At heights below 5ft 10in, 77.8kg places you in the overweight or obese categories. At heights above 5ft 10in, this weight sits comfortably within the healthy range. Use our free weight converter and BMI calculator above to check your exact BMI instantly.
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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 and Limitations
The NHS categorises BMI as follows: healthy weight (18.5–24.9), overweight (25.0–29.9), obese (30.0–34.9), and severely obese (40.0+). However, BMI has important limitations. It does not distinguish between muscle and fat — an athlete with high muscle mass may have an elevated BMI despite low body fat. BMI also does not account for where fat is stored; waist circumference is equally important for assessing health risk. Adults of South Asian, Chinese, Black African, or Black Caribbean heritage face higher health risks at the same BMI, so the NHS recommends lower thresholds for these groups. Always discuss your personal weight and health with your GP, who can provide tailored advice based on your full 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 77.8kg in stones and pounds?
77.8kg equals 12 stone 2 pounds (12st 2lbs) or 171.4 lbs. To convert kilograms to stone, divide by 6.35029. To convert kg to pounds, multiply by 2.20462. You can use our free weight converter above for instant conversions between metric and imperial measurements.
Is 77.8kg a healthy weight?
It depends on your height. At 5ft 10in or taller, 77.8kg is within the healthy BMI range (18.5–24.9). At shorter heights, it falls into the overweight or obese categories. Use our BMI calculator to check your personal BMI instantly based on your exact height and weight.
What BMI is 77.8kg at 5ft 6in?
At 5ft 6in (168cm), 77.8kg gives a BMI of 27.5, which falls into the overweight category (25.0–29.9). The NHS recommends a healthy BMI of 18.5–24.9. A healthy weight range at this height is approximately 51–66kg.
Can I use BMI alone to assess my health?
No. BMI is a useful screening tool but has significant limitations. It does not distinguish muscle from fat, and does not account for waist circumference or where fat is stored. Waist measurement is equally important — the NHS recommends measuring waist circumference as part of a full health assessment. Always discuss your weight with your GP.
Are BMI thresholds different for certain ethnic backgrounds?
Yes. The NHS recommends lower BMI thresholds for adults of South Asian, Chinese, Black African, or Black Caribbean heritage, as these groups have higher risks of type 2 diabetes and cardiovascular disease at the same BMI. A healthy BMI for these groups is 18.5–22.9 rather than 18.5–24.9.
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.