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 Does a BMI of 34 Mean According to NHS Guidelines?
A BMI of 34 falls into the obese category according to NHS classifications. This means your weight carries increased health risks, but the good news is that NHS weight management support is available to help. Even modest weight loss of 5–10% can deliver meaningful health benefits. Your GP can assess your individual circumstances, discuss any weight-related health conditions you may have, and signpost you to appropriate NHS support. Use our free BMI calculator above to confirm your personal BMI and explore your healthy weight range for your height.
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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.
NHS BMI Categories and What They Mean
The NHS BMI classification system divides adults into five main categories based on the bmi formula (weight in kg divided by height in metres squared). A BMI of 34 places you in the obese (Class I) category, which runs from 30.0 to 34.9. This category indicates elevated health risks compared to the healthy weight range of 18.5 to 24.9.
It's important to remember that BMI has limitations — it does not distinguish between muscle and fat, nor does it account for where fat is stored on your body. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds because these groups face higher cardiovascular and type 2 diabetes risks at the same BMI level.
- Healthy BMI: 18.5–24.9
- Overweight: 25.0–29.9
- Obese Class I: 30.0–34.9 (your range)
- Obese Class II: 35.0–39.9
- Severely obese: 40.0 and above
You can also use the weight converter on this page to check your weight in stone, pounds, or kilograms to understand your current measurement in different units.
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 Weight Management Pathway and Support Available
If you have a BMI of 34, the NHS recommends discussing weight management with your GP. The NHS weight management pathway typically works through four tiers: self-help and digital tools (Tier 1), primary care support and behaviour change programmes (Tier 2), specialist multidisciplinary weight management services (Tier 3), and bariatric surgery in complex cases (Tier 4).
Your GP can assess whether you have any weight-related health conditions — such as type 2 diabetes, high blood pressure, sleep apnoea, or cardiovascular disease — which may make you eligible for prescription weight loss support. Access to specialist NHS weight management services does vary by region, and waiting lists can be lengthy in some areas. Your GP can discuss all available options and refer you to the appropriate service. Many people find that tracking progress with our free progress tracker helps maintain motivation and accountability throughout their weight management journey.
- 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.
Is a BMI of 34 dangerous?
A BMI of 34 carries increased health risks compared to the healthy range, but it is not an immediate emergency. Risk increases with other factors like waist circumference, blood pressure, and existing health conditions. Your GP can assess your individual risk profile and discuss appropriate support. Even 5–clinically studied weight loss can reduce these risks significantly.
What health conditions are linked to a BMI of 34?
A BMI in the obese range increases risk of type 2 diabetes, high blood pressure, heart disease, certain cancers, sleep apnoea, and joint problems. These risks increase further if you also have a large waist circumference or existing health conditions. Your GP can screen for these and advise on next steps.
Can I get weight loss medication on the NHS with a BMI of 34?
Yes, you may be eligible for prescription weight loss medication through NHS specialist services if you also have weight-related health conditions or a BMI of 35 or above. Regional availability varies. Your GP can refer you to tier 3 specialist weight management services, which can prescribe medications like tirzepatide (Mounjaro) or semaglutide (Wegovy) alongside lifestyle support.
What's the healthy weight range if my BMI is 34?
Your healthy weight range depends on your height. Calculate it using our free BMI calculator on this page — enter your height, and it will show the kg and stone range for a healthy BMI of 18.5–24.9. For most people, reaching the healthy range involves gradual, sustainable weight loss of 0.5–1 kg per week.
Should I start dieting immediately if my BMI is 34?
Before starting any weight loss programme, discuss your plans with your GP. They can assess your overall health, identify any underlying conditions, and recommend evidence-based approaches. Sustainable weight loss combines a modest calorie deficit with increased physical activity. Very restrictive dieting is not recommended without medical supervision.
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.