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
Is 7.5kg in Stones a Healthy Weight?
7.5kg converts to 1 stone 2.4lbs — but whether this is a healthy weight depends entirely on your height. A weight that's healthy for one person may be overweight or underweight for another. Using our free BMI calculator and weight converter above, you can check your personal BMI and see where your weight falls on the NHS healthy weight scale. This guide shows you practical examples at different heights so you can understand what healthy means 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.
Healthy Weight Ranges at Different Heights
At 7.5kg, you're at a very light weight — for most adults, this would be significantly underweight. However, context matters. Here are three concrete examples:
- At 150cm (4ft 11in): 7.5kg gives a BMI of 3.3 — severely underweight. Healthy weight range: 41–54kg (6st 6lbs to 8st 7lbs).
- At 165cm (5ft 5in): 7.5kg gives a BMI of 2.8 — severely underweight. Healthy weight range: 50–68kg (7st 12lbs to 10st 11lbs).
- At 180cm (5ft 11in): 7.5kg gives a BMI of 2.3 — severely underweight. Healthy weight range: 60–81kg (9st 6lbs to 12st 11lbs).
According to NHS guidelines, a healthy BMI sits between 18.5 and 24.9. Use our weight converter to check your exact stone and pounds equivalent, then calculate your BMI using the free tool on this page to see your personal health category.
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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.
What to Do If Your Weight Is Outside the Healthy Range
If you're significantly underweight at 7.5kg, it's important to speak with your GP. Being very underweight can indicate nutritional deficiencies, underlying health conditions, or other concerns that need professional assessment. Your GP can review your health history, check for medical causes, and refer you to a dietitian if needed.
If you're at a healthy weight but want to monitor your progress, our free progress tracker helps you log weight changes over time. Remember that weight is just one health marker — waist circumference also matters. The NHS recommends keeping waist measurements below 94cm for men and 80cm for women to reduce health risks.
- 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.
How do I convert 7.5kg into stones and pounds?
7.5kg equals approximately 1 stone and 2.4lbs. To convert kilograms to stone, divide by 6.35. Use our weight converter above to instantly switch between kg, stone, and pounds. This makes it easy to understand your weight in UK measurements.
Is 7.5kg a healthy weight for an adult?
At 7.5kg, this would be severely underweight for any adult regardless of height. A healthy adult weight varies greatly by height and build. Use our free BMI calculator to check your personal BMI and compare it against NHS healthy weight ranges. Most UK adults weigh significantly more than 7.5kg.
What's the healthy weight range for my height?
Healthy weight depends on your height. The NHS healthy BMI range is 18.5–24.9. For example, at 5ft 6in (168cm), healthy weight is approximately 52–70kg (8st 2lbs to 11st 0lbs). Enter your height into our BMI calculator above to find your exact healthy weight range.
What should I do if I'm significantly underweight?
If you're severely underweight, speak with your GP. Being well below a healthy weight can indicate nutritional issues or underlying health conditions that need professional assessment. Your GP can check your health, review your medical history, and refer you to a dietitian for personalised guidance.
Why does weight vary so much between people of different heights?
Body weight is related to height because taller people have more body mass. BMI accounts for this relationship by dividing weight by height squared. This is why the same weight (7.5kg) is severely underweight for everyone — because healthy adult weights are much higher. NHS BMI guidelines help put weight in proper context.
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.