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
Target Weight Calculator for UK Adults
Setting a realistic target weight is one of the most important steps in any weight management journey. Whether you're looking to improve your health, reduce disease risk, or feel more confident, knowing what a healthy weight means for your body is essential. This guide explains how to calculate your target weight using NHS guidelines, and shows you how to use our free tools to work out realistic goals based on your individual circumstances.
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 Target Weight Using NHS Standards
The NHS defines a healthy weight using Body Mass Index (BMI), which takes both your weight and height into account. A BMI between 18.5 and 24.9 is considered healthy for most UK adults. However, for people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a lower range of 18.5 to 22.9, as these groups face higher health risks at the same BMI level.
To find your target weight range, your height is the starting point. For example, at 5ft 8in (173cm), a healthy weight range is approximately 55.4kg to 74.5kg (8st 10lbs to 11st 10lbs). Our free BMI calculator above will instantly calculate your personal healthy weight range — simply enter your height and current weight to see where you sit on the NHS scale.
It's important to remember that not everyone's ideal weight is the same. Muscle mass, bone density, age, and fitness level all play a role. Your target weight should be one that you can sustain long-term and that supports your overall health, not just a number on the scales.
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.
UK Weight Management Tools and GP Support
MyWeightCheck provides several free tools to help you manage your weight effectively. Use our weight converter to switch between kilograms, stone, and pounds — essential for understanding UK weight guidance. Our BMI calculator gives you instant feedback on where your target weight sits within NHS categories.
If you're considering weight loss support, our GLP-1 weight loss calculator can help you explore potential outcomes with prescription weight management options. However, the best first step is always to speak to your GP. They can assess your individual health, discuss realistic targets, and signpost you to NHS weight management services in your area. Many regions offer free tier 1 and 2 support through primary care or community programmes.
- 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 should my target weight be?
Your target weight depends on your height, age, muscle mass, and health conditions. The NHS healthy BMI range (18.5–24.9) provides a framework, but your GP can help you set a realistic goal. For South Asian, Black African, or Black Caribbean adults, lower BMI thresholds (18.5–22.9) apply. Use our BMI calculator to find your healthy range.
How do I calculate my target weight from my height?
Multiply your height in metres by itself, then multiply by 18.5 for the lower healthy bound and 24.9 for the upper bound. For example, at 1.73m: lower target = 18.5 × (1.73)² = 55.4kg; upper target = 24.9 × (1.73)² = 74.5kg. Our free BMI calculator does this instantly.
Can I reach my target weight safely?
Yes, if you lose weight gradually at 0.5–1kg per week. This involves a calorie deficit of around 500 kcal per day through diet and physical activity. Faster weight loss risks muscle loss. Your GP can advise on safe approaches, including referral to NHS tier 3 weight management services if needed.
What if my target weight feels too ambitious?
Even losing 5–10% of your current weight brings significant health benefits — lower blood pressure, improved blood sugar control, and reduced joint strain. You don't need to reach the bottom of the healthy range to improve your health. Your GP or a weight management specialist can help you set stepwise goals.
Should I use a weight loss calculator to plan my target?
Yes. Our GLP-1 weight loss calculator can help you explore potential timelines and outcomes if you're considering prescription weight management. However, combine this with our BMI calculator and weight converter to understand your current position and healthy range within NHS guidelines.
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.