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 Optimum Height and Weight for UK Adults?
Your optimum height and weight depends on your individual body composition, age, and health status — not a single target number. The NHS uses BMI (body mass index) as a screening tool to determine healthy weight ranges for your height. For most UK adults, a healthy BMI falls between 18.5 and 24.9, though people of South Asian, Chinese, Black African, or Black Caribbean heritage may have different thresholds. Use our free BMI calculator to find your personal healthy weight range instantly, and explore how your height and weight interact with your overall health through nhs guidance specific to the UK.
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.
How to Calculate Your Optimum Weight Range
Your healthy weight range is calculated using your height in metres. The NHS provides a simple formula: multiply your height by itself, then multiply by 18.5 for the lower healthy weight limit, and by 24.9 for the upper limit.
- Example: If you are 1.75m tall, a healthy BMI gives a weight range of approximately 55kg to 76kg (8st 9lbs to 11st 13lbs)
- South Asian adults: Lower thresholds apply — healthy BMI ranges from 18.5 to 22.9, which may shift your optimum weight downwards
- Limitations: BMI does not account for muscle mass, so athletes or very muscular individuals may have a higher BMI while remaining healthy
Our weight converter tool lets you switch between kg, stone, and pounds instantly, making it easy to understand your healthy range in whichever unit you prefer.
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.
Factors Beyond Height and Weight
While height and weight are important, waist circumference and body composition also matter significantly for health. The NHS recommends measuring your waist to assess abdominal fat, which carries greater health risks than fat stored elsewhere.
- Waist-to-height ratio: A ratio below 0.5 (waist circumference ÷ height) is considered healthy for all adults
- Weight distribution: Where you carry weight affects your health risk more than BMI alone
- Individual variation: Age, genetics, fitness level, and existing health conditions all influence what your personal optimum weight should be
Your GP can give you personalised guidance on whether your height and weight combination is healthy for your specific circumstances and medical history.
- 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 the optimum weight for my height in the UK?
Your optimum weight depends on your height, age, body composition, and genetics. Use the NHS BMI categories: a healthy BMI is 18.5–24.9. Calculate your healthy range by multiplying your height (m) by itself, then multiply by 18.5 for lower limit and 24.9 for upper limit. Our BMI calculator above does this instantly for you.
How much should I weigh if I am 5ft 8in tall?
At 5ft 8in (1.73m), a healthy weight range is approximately 55kg to 76kg (8st 10lbs to 11st 13lbs) based on BMI 18.5–24.9. However, this varies by frame size and muscle mass. Use our weight converter to switch between kg and stone, then consult your GP for personalised guidance.
Is there a difference between optimum weight for men and women?
BMI categories are the same for men and women, but average healthy weights differ due to height differences. UK women are on average slightly shorter than men, so typical healthy weight ranges are lower. Body composition, fitness, and genetics matter more than gender alone.
What does optimum height and weight mean for health?
Optimum height and weight refers to a weight range where your BMI sits within NHS healthy categories (18.5–24.9), reducing your risk of weight-related diseases like type 2 diabetes and heart disease. However, BMI is just one screening tool — waist circumference, fitness, and overall lifestyle matter too.
Should I aim for a specific weight number?
Rather than targeting a specific weight, aim for a healthy BMI range, which accounts for your unique height. Losing even 5–10% of your body weight can improve health significantly. Our free progress tracker helps you monitor sustainable changes over time alongside lifestyle improvements.
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.