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
Healthy Weight Loss Per Week — NHS Recommendations
The NHS recommends losing weight at a rate of 0.5 to 1 kg (1 to 2 lbs) per week for sustainable, healthy results. This moderate pace helps preserve muscle mass, prevents nutritional deficiencies, and creates habits you can maintain long-term. Weight loss at this speed typically reflects a calorie deficit of around 500 kcal per day, which is safe for most adults. However, the ideal weight loss rate depends on your starting point, current BMI, and individual health factors. Your GP can advise on what's right for you.
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 Weight Loss Links to Healthy BMI Goals
A healthy BMI for UK adults is between 18.5 and 24.9, according to NHS guidelines. Your ideal body weight depends on your height, so your target weight loss varies accordingly. For example, at 5ft 8in (173cm), a healthy weight range is approximately 55 to 75kg (8st 8lbs to 11st 10lbs). At 5ft 4in (163cm), the healthy weight range is roughly 49 to 66kg (7st 10lbs to 10st 5lbs). If your current BMI is in the overweight (25–29.9) or obese (30+) range, losing weight to reach the 18.5–24.9 range brings significant health benefits. Use our free BMI calculator above to find your current BMI and calculate your personal healthy weight range based on your exact height.
- Losing 0.5–1kg per week typically reduces BMI by 0.15–0.3 points per week
- Even a 5–10% reduction in body weight improves blood pressure, blood sugar, and cholesterol
- South Asian, Chinese, Black African, and Black Caribbean adults have lower healthy BMI thresholds (18.5–22.9), so target weight ranges differ
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.
Using the BMI Framework to Track Your Progress
The most practical way to monitor healthy weight loss is to track your BMI alongside weight itself. At 0.5–1kg per week, you should see your BMI drop by approximately 0.15–0.3 points per week—modest but measurable progress toward your healthy weight range. Rather than fixating on weekly scales, many people find it more motivating to check their BMI monthly and measure progress in dress sizes or how clothes fit, as these changes often precede major scale shifts. Our free progress tracker lets you log your weight weekly and watch your BMI move toward the healthy range. This framework keeps weight loss in health context rather than appearance focus. Remember: BMI has limitations—it doesn't account for muscle mass—but it's a reliable screening tool when used alongside waist circumference and how you feel.
- 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.
Is losing 0.5kg per week assured to happen?
No. Weight loss varies week to week due to water retention, hormones, and individual metabolism. An average of 0.5–1kg per week over several weeks is more realistic than every single week. Consistency matters more than perfection. If you're not losing weight at this rate after 4–6 weeks, your GP can review your approach.
What if I want to lose weight faster?
Very gradual weight management (more than 1.5kg per week) without medical supervision risks muscle loss, nutritional deficiencies, and fatigue. If you have significant weight to lose or health complications, your GP may recommend a supervised very low calorie diet (VLCD) or referral to specialist weight management services, including prescription options.
Does the healthy weight loss rate change if I'm very obese?
Individuals with a BMI over 40 may initially lose weight faster than 1kg per week (sometimes 1–2kg weekly), which is normal and safe when supervised. Your BMI will drop more noticeably at first. As you approach the overweight range, the rate typically slows to 0.5–1kg per week, which is sustainable long-term.
How do I calculate my healthy weight range for my height?
Multiply your height in metres squared by 18.5 and 24.9. For example, at 1.73m: 18.5 × 1.73² = 55kg (lower), and 24.9 × 1.73² = 75kg (upper). The free BMI calculator on this page does this instantly—just enter your height and it shows your healthy weight range in kg and stone.
Can weight loss injections help me lose weight at a healthy rate?
GLP-1 medications like Wegovy and dual GIP/GLP-1 injections like Mounjaro are prescribed alongside reduced-calorie diet and activity. They may help achieve the 0.5–1kg per week target by reducing hunger and cravings. They're prescription-only, require clinical assessment, and work best with lifestyle changes, not instead of them.
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.