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 the Perfect Weight for a Woman in the UK?
There's no single "perfect" weight for every woman — it depends on your height, age, muscle mass, and individual health. The NHS uses BMI (Body Mass Index) to define healthy weight ranges, and these vary by ethnicity and personal circumstances. Using our free BMI calculator, you can discover whether your current weight falls within the healthy range for your height. This guide explains UK health guidance on weight management and how to find the right approach for you.
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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.
Understanding Healthy Weight for UK Women
The NHS defines a healthy weight as a BMI between 18.5 and 24.9 for most adults. However, this isn't a fixed number — it's a range based on your height. For example, a healthy weight for a woman who is 5ft 4in (163cm) typically falls between approximately 50kg (7st 12lbs) and 67kg (10st 8lbs). For a woman who is 5ft 8in (173cm), the healthy range is roughly 54kg (8st 7lbs) to 73kg (11st 7lbs).
For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds due to higher health risks at lower weights. Your GP can help you understand what healthy weight means for your specific circumstances, including any existing health conditions.
- BMI 18.5–24.9 = healthy weight
- BMI 25–29.9 = overweight
- BMI 30+ = obese (with subcategories)
Waist circumference also matters. For women, a waist measurement over 80cm (31.5in) suggests increased health risk; over 88cm (34.5in) suggests high risk — regardless of BMI. Use our weight converter to translate your weight into stone, lbs, or kg, and use our BMI calculator to check your personal BMI instantly.
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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.
Why There's No Single "Perfect" Weight
Healthy weight varies dramatically between individuals because it depends on height, age, muscle mass, bone density, genetics, and medical history. Two women of identical height and weight can have very different body compositions — one may have more muscle (which weighs more than fat), the other more fat. This is why BMI, while useful, has limitations and shouldn't be viewed in isolation.
Rather than chasing a number on the scales, UK health guidance focuses on weight management — maintaining a weight that supports good health and reduces your risk of type 2 diabetes, heart disease, and other weight-related conditions. Many women find it helpful to track their progress over time using our free progress tracker, which shows changes week to week rather than fixating on a single target number. Your GP can provide personalised health advice based on your individual 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 considered a healthy weight for a woman in the UK?
The NHS defines healthy weight as a BMI between 18.5 and 24.9. The exact kilogramme or stone amount depends on your height. For women of South Asian, Black African, Caribbean, or Chinese heritage, the NHS recommends a lower healthy BMI range (18.5–22.9) due to higher cardiovascular risk at standard thresholds. Your GP can advise on your personal healthy weight range.
Is there such a thing as a "perfect" weight?
No — there's no universal perfect weight. Healthy weight varies by height, age, muscle mass, genetics, and health status. Two people of identical weight can have different body compositions and health outcomes. Focus on achieving a weight within the NHS healthy BMI range for your height, rather than a specific number.
How do I calculate my healthy weight range?
Use our free BMI calculator to find your healthy weight range based on your height instantly. Alternatively, multiply your height in metres squared by 18.5 and 24.9 to find the lower and upper bounds of a healthy weight. For example, at 5ft 6in (1.68m), healthy weight is roughly 52–70kg (8st 3lbs–11st 0lbs).
Does waist measurement matter as much as weight?
Yes — waist circumference is an important indicator of health risk independent of BMI. For women, a waist over 80cm (31.5in) suggests increased risk; over 88cm (34.5in) suggests high risk. Both weight and waist measurement are important for understanding your health picture.
Should I aim for a specific weight or focus on health markers?
Health-focused weight management is better than chasing a single target number. Focus on reducing health risks, improving energy levels, and supporting sustainable lifestyle changes. Your GP or a weight management service can help you set realistic goals. Track your progress over time — even a 5–clinically studied weight loss can deliver significant health benefits.
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.