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
BMI Chart in Kg — NHS Health Categories and Ranges
A BMI chart in kg helps you understand where your weight falls on the NHS health scale. Whether you're checking if you're within a healthy range or tracking progress towards a weight management goal, knowing your BMI category in kilograms is a practical first step. Use our free BMI calculator above to find your exact BMI, then refer to this NHS-aligned chart to see where you sit and what it means for your health.
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.
NHS BMI Categories and Weight Ranges in Kg
The NHS BMI categories apply to all UK adults aged 18 and over. Your BMI is calculated by dividing your weight in kg by your height in metres squared. Here's the standard NHS BMI chart in kg:
- Underweight: BMI below 18.5 (typically under 56 kg for someone 175cm tall)
- Healthy weight: BMI 18.5 to 24.9 (typically 56–74 kg for 175cm)
- Overweight: BMI 25 to 29.9 (typically 74–88 kg for 175cm)
- Obese (Class I): BMI 30 to 34.9 (typically 88–103 kg for 175cm)
- Obese (Class II): BMI 35 to 39.9 (typically 103–117 kg for 175cm)
- Severely obese (Class III): BMI 40 and above (typically 117 kg and above for 175cm)
For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds due to higher health risks at lower weights. Healthy weight for these groups is BMI 18.5–22.9 kg/m², and overweight begins at BMI 23 kg/m².
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.
When to Seek Help from Your GP — NHS Weight Management Pathway
If your BMI places you in the overweight or obese range, your GP can discuss whether you'd benefit from NHS weight management support. The NHS offers a structured pathway: Tier 1 covers self-help and digital tools (like the BMI calculator on this page), Tier 2 includes primary care behaviour change programmes, and Tier 3 involves specialist weight management services where prescription medication or intensive support may be considered. Even small weight reductions of 5–10% can improve blood pressure, blood sugar, and joint health. Use the weight converter on this page to track progress in kg or stone as you prefer.
- 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 does my BMI in kg actually tell me?
Your BMI indicates whether your weight is within a healthy range for your height according to NHS guidelines. It helps identify potential health risks associated with being underweight, overweight, or obese. However, BMI doesn't account for muscle mass, bone density, or where fat is stored—your GP can provide personalised interpretation.
Are the BMI categories in kg different from other measurements?
No. BMI is calculated the same way whether you use kg or pounds—the result is the same. The NHS chart remains identical; it's just the weight input that differs. Use our free weight converter to switch between kg, stone, and pounds easily.
Why does the NHS have different BMI ranges for some ethnic groups?
People of South Asian, Chinese, Black African, and Black Caribbean heritage have been shown to develop weight-related health conditions like type 2 diabetes at lower BMI levels. The NHS recommends lower thresholds (healthy range 18.5–22.9 instead of 18.5–24.9) to reflect this increased cardiovascular and metabolic risk.
Should I aim to be at the bottom or middle of the healthy BMI range in kg?
Anywhere within the NHS healthy BMI range (18.5–24.9) is considered healthy. The ideal weight for you depends on factors like muscle mass, bone structure, and overall health. Your GP or a registered dietitian can advise what's right for your individual circumstances.
What if I'm just over the healthy BMI threshold—do I need to lose weight?
Not necessarily immediately. A BMI just above 24.9 (overweight category) doesn't automatically require weight loss, especially if you have no weight-related health conditions. Your GP can assess your overall cardiovascular health, blood pressure, and family history to advise whether losing weight would benefit you personally.
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.