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 Is a Normal Body Weight for Adults?
Normal body weight varies considerably between individuals based on height, age, gender, and ethnicity. Rather than a single "normal" number, health professionals use ranges to define healthy weight — typically measured through BMI (body mass index) and healthy weight guidelines set by the NHS. For most UK adults, a normal or healthy weight falls within a BMI of 18.5 to 24.9, though people from South Asian, Chinese, Black African, or Black Caribbean backgrounds may have different thresholds. Our free BMI calculator above can help you check whether your weight falls within the healthy range for your specific height.
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 Healthy Weight Ranges and BMI Categories
The NHS defines healthy weight using BMI categories that apply to all UK adults. A BMI between 18.5 and 24.9 is considered a healthy weight, whilst 25 to 29.9 is classed as overweight, and 30 and above as obese. However, BMI has important limitations — it doesn't distinguish between muscle and fat, so athletic individuals with high muscle mass may have a higher BMI but still be in excellent health. For more precise assessment, your GP may also measure your waist circumference: for men, over 94cm indicates increased health risk; for women, over 80cm indicates increased risk. To convert your weight between kg and stone using standard measurements, try our free weight converter above. These NHS thresholds apply to adults aged 18 and over; children use different growth-based centile charts.
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.
Healthy Weight by Height — Practical Examples
Your healthy weight range depends entirely on your height. For example, an adult who is 5ft 8in (173cm) tall would have a healthy weight range of approximately 55–74kg (8st 8lbs to 11st 9lbs). Someone 5ft 4in (163cm) tall would fall into a healthy range of about 49–66kg (7st 10lbs to 10st 5lbs). These ranges apply to most adults regardless of gender, though some variation exists. If you're unsure whether your weight is healthy for your height, use our free BMI calculator to find your personal healthy weight range instantly. Remember that these are guidelines — your GP may consider other factors including your age, medical history, fitness level, and where excess weight is stored on your body.
- 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's the difference between normal weight and healthy weight?
The terms are often used interchangeably. "Healthy weight" is the clinical term used by the NHS, defined by BMI 18.5–24.9. "Normal weight" is more informal but means the same thing — a weight associated with lower health risks. Both terms describe the same BMI category and are suitable for general use.
Do ethnic background and age affect normal weight ranges?
Yes, significantly. The NHS recommends lower BMI thresholds for people of South Asian, Chinese, Black African, or Black Caribbean heritage — starting at 18.5–22.9 for healthy weight — because these groups face higher diabetes and heart disease risk at lower BMI levels. Age also matters; older adults may have different body composition considerations, so discuss your personal healthy weight with your GP.
Is BMI the only way to assess if my weight is normal and healthy?
No. BMI is a useful screening tool but has limitations. Your GP may also assess waist circumference (where fat is stored matters for health risk), fitness level, blood pressure, cholesterol, and blood sugar. For a complete picture of your health, always consult your GP rather than relying on BMI alone.
How do I use my height to find my normal weight range?
The healthy weight range formula is: lower bound = 18.5 × height(m)², upper bound = 24.9 × height(m)². For example, at 1.73m tall, healthy weight is 55–74kg. Our free BMI calculator above does this instantly — just enter your height and it will show your healthy weight range in both kg and stone.
If my weight is above the normal range, what should I do?
If you're overweight or obese according to NHS guidelines, speak to your GP. They can assess your overall health, discuss lifestyle changes, and — if appropriate — refer you to weight management services. The NHS provides free weight loss support programmes. Your GP can also advise whether prescription weight management treatment might help your situation.
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.