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
What's Your BMI at 91 Kg?
At 91 kg (200.6 pounds), your BMI depends entirely on your height. Someone who is 5ft 4in (163cm) will have a very different BMI than someone who is 6ft 2in (188cm) at this same weight. Use our free BMI calculator above to find your personal BMI instantly, or see how this weight converts across different heights below. Your BMI then tells you where you fall within NHS health categories — underweight, healthy weight, overweight, or obese. Understanding your BMI is a useful first step toward assessing your health, though it's important to remember that BMI has limitations and doesn't account for muscle mass or where fat is stored.
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.
91 Kg BMI at Different Heights
91 kg (200.6 lbs) gives different BMI values depending on your height. Here are BMI examples at typical UK heights:
- 5ft 0in (152cm): BMI 39.4 (Obese Class II)
- 5ft 4in (163cm): BMI 35.2 (Obese Class I)
- 5ft 8in (173cm): BMI 31.4 (Obese Class I)
- 5ft 10in (178cm): BMI 29.0 (Overweight)
- 6ft 0in (183cm): BMI 27.1 (Overweight)
- 6ft 2in (188cm): BMI 25.5 (Healthy weight)
To convert 91 kg to stone, divide by 6.35 — this equals approximately 14 stone 5 pounds. Use our free weight converter above to switch between kg, stone, and pounds instantly.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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 & What They Mean
The NHS defines BMI categories as follows: Healthy weight is 18.5–24.9, overweight is 25.0–29.9, obese (Class I) is 30.0–34.9, and severely obese (Class III) is 40.0+. At 91 kg, whether you fall into the overweight or obese category depends on your height — taller individuals will have lower BMIs. It's important to remember that BMI is a screening tool with limitations. It doesn't distinguish between muscle and fat, so athletes may have a high BMI despite low body fat percentage. Waist circumference (ideally under 94cm for men, 80cm for women) is also a valuable health indicator.
- 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 91 kg to pounds?
Multiply 91 kg by 2.20462. This equals 200.6 pounds (or approximately 200 lbs). To convert to stone and pounds, divide by 6.35029, giving you 14 stone 5 pounds. Our free weight converter on this page does this instantly.
Is 91 kg overweight or obese?
This depends on your height. At 5ft 8in, 91 kg gives a BMI of 31.4 (obese). At 6ft 0in, it's 27.1 (overweight). At 6ft 2in, it's 25.5 (healthy weight). Use our free BMI calculator above to find your personal category based on your height.
What is a healthy weight at 5ft 8in?
A healthy BMI (18.5–24.9) at 5ft 8in (173cm) equals roughly 55–74 kg (121–163 lbs or 8st 8lbs–11st 9lbs). Our BMI calculator above shows the exact healthy weight range for your height instantly.
Can I use BMI to assess my health?
BMI is a useful screening tool but has limitations. It doesn't account for muscle mass, bone density, or fat distribution. A high BMI may indicate health risk, but athletes or very muscular individuals may have high BMI despite good health. Always discuss your personal health with your GP.
How does ethnicity affect BMI categories?
The NHS recommends lower BMI thresholds for South Asian, Chinese, Black African, and Black Caribbean adults due to higher health risks at lower BMI levels. For these groups, healthy weight is 18.5–22.9, and overweight starts at 23.0. Discuss your individual thresholds with your GP.
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.