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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66.6kg to Stone — Healthy Weight Guide
66.6kg converts to approximately 10 stone and 6.5 pounds (10st 6.5lbs) — but whether this is a healthy weight depends entirely on your height. Using NHS BMI guidelines, the same weight can be healthy for a tall person or overweight for a shorter person. This guide shows you exactly how to check if 66.6kg falls within the healthy weight range for your individual height, plus practical next steps if you're concerned about your weight. Use our free BMI calculator above to check your personal BMI instantly based on your exact measurements.
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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
To understand whether 66.6kg is healthy for you, you need to know your height. Here's how weight in stone converts across three common heights:
- At 5ft 4in (163cm): 66.6kg gives a BMI of 24.8 — within the healthy weight range (18.5–24.9). This weight is healthy.
- At 5ft 7in (170cm): 66.6kg gives a BMI of 23.3 — healthy weight range. No concern.
- At 5ft 1in (155cm): 66.6kg gives a BMI of 27.8 — overweight range (25–29.9). This weight would be above the healthy range.
The NHS BMI categories for adults are: healthy weight (18.5–24.9), overweight (25–29.9), and obese (30+). Remember that BMI doesn't account for muscle mass or where fat is stored, so your GP can provide personalised advice. Use the weight converter to see 66.6kg in different units, then calculate your BMI with our free tool to check where you stand.
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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 the NHS Says About Healthy Weight
The NHS recommends that adults aim for a BMI between 18.5 and 24.9 for optimal health. However, for adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower thresholds apply — a healthy BMI starts at 18.5 but caps at 22.9, because these groups face higher health risks at higher BMI levels.
Beyond BMI, waist measurement also matters. For men, a waist over 94cm (37in) signals increased risk; for women, over 80cm (31.5in) indicates increased risk. If your weight feels concerning or you're unsure whether 66.6kg is right for you, speak to your GP. They can assess your individual health, consider your family history and medical conditions, and suggest appropriate next steps — whether that's lifestyle support, referral to a weight management service, or monitoring.
- 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 66.6kg in stone and pounds?
66.6kg converts to 10 stone 6.5 pounds (10st 6.5lbs). To convert kilograms to stone, divide the kg value by 6.35029. You can also use our free weight converter on this page to switch between kg, stone, and pounds instantly.
Is 66.6kg a healthy weight?
It depends on your height. At 5ft 7in, 66.6kg is healthy. At 5ft 1in, it's overweight. Calculate your personal BMI using your height and weight with our free BMI calculator above — it will tell you instantly where you fall on the NHS healthy weight scale.
What is the healthy weight range for my height?
A healthy BMI is 18.5–24.9 according to NHS guidelines. To find your healthy weight range, multiply your height in metres squared by 18.5 (lower bound) and 24.9 (upper bound). Your GP or a weight management service can give you personalised guidance for your specific circumstances.
Should I be concerned about my weight at 66.6kg?
Not necessarily — context matters. Check your BMI first using our calculator. If you're within the healthy range, no action is needed. If you're overweight or obese, consider speaking to your GP about weight management support. Remember, sustainable changes to diet and physical activity matter more than the number on the scales.
What should I do if my weight is outside the healthy range?
Contact your GP for personalised advice. They can assess your overall health, discuss any underlying conditions, and refer you to NHS weight management services if appropriate. The NHS provides free support including diet and exercise programmes, and access to prescription weight loss medications where eligible. Track your progress using our free progress tracker.
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.