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 Your Desired Weight For Your Height?
Your desired weight for height depends on your individual health, muscle mass, and frame size — not a single number. The NHS provides healthy weight ranges based on BMI, which accounts for both height and weight together. For any given height, there's a range of weights that fall into the healthy category. Using our free BMI calculator, you can find where your current weight sits and what healthy weight management means for you specifically.
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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 Healthy Weight Ranges For Height
The NHS defines healthy weight using BMI categories: a healthy BMI falls between 18.5 and 24.9 kg/m². This means for each height, there is a weight range that corresponds to healthy BMI. For example, at 1.70m (5ft 7in) tall, a healthy weight range is approximately 53–72 kg (8st 5lbs to 11st 4lbs). At 1.75m (5ft 9in), the range is 56–76 kg (8st 12lbs to 12st). These ranges account for natural variation in body composition, bone density, and muscle mass.
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends slightly lower thresholds due to higher health risk at lower BMI levels — a healthy BMI for these groups starts at 18.5 but extends only to 22.9. Your GP can advise on which guidance applies to you. Use our weight converter to switch between kg, stone, and lbs 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.
Calculating Your Personal Healthy Weight Range
To find your healthy weight range, you need your height in metres. Multiply your height by itself, then multiply by 18.5 (lower bound) and 24.9 (upper bound). For example, at 1.65m: 1.65 × 1.65 = 2.7225, then 2.7225 × 18.5 = 50.4 kg and 2.7225 × 24.9 = 67.8 kg. This gives a healthy range of 50–68 kg (7st 12lbs to 10st 10lbs).
Remember: this is a starting point. Your ideal weight also depends on muscle mass, bone structure, and overall health. Rather than focusing on a single desired weight, aim for a healthy BMI range. Our free BMI calculator above can instantly show your personal healthy weight range for your exact height. Your GP can also provide personalised guidance on weight management and nhs health advice tailored to your circumstances.
- 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 difference between healthy weight and desired weight?
Healthy weight is based on scientific guidelines (BMI 18.5–24.9) and refers to a weight range associated with lower health risks. Desired weight is personal — it might be influenced by appearance, fitness goals, or how you feel. The two don't always align. Focus on achieving a healthy weight range first; your desired weight may shift as you achieve health benefits.
Can I use a weight converter to find my healthy weight?
A weight converter helps you switch between kg, stone, and lbs so you can understand your weight in the units you prefer. However, a converter doesn't calculate healthy weight ranges — you need to use a BMI calculator for that. Our weight converter and BMI calculator work together to give you the full picture of your health status.
Does my desired weight depend on my age?
BMI categories remain the same across adulthood, so the healthy weight range for your height doesn't change significantly with age. However, muscle mass naturally decreases with age, so you may need to adjust your fitness and diet approach. Your GP can advise on age-specific health goals and weight management strategies.
What if my desired weight is below the healthy BMI range?
If your target weight falls below BMI 18.5 (underweight), discuss this with your GP. Being underweight carries health risks including nutrient deficiency, weakened immunity, and bone loss. Your GP can help you set a realistic, healthy weight goal and provide support for achieving it safely.
How can I track progress toward my desired weight?
Set a realistic goal within the healthy weight range for your height. Use our free progress tracker to log your weight over time and see trends. Track alongside lifestyle changes like diet and activity. Remember that weight fluctuates daily due to hydration, hormones, and digestion — focus on weekly trends rather than daily numbers.
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.