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
How Can I Calculate Weight in the UK?
Calculating your weight and understanding what it means for your health is straightforward with the right tools and guidance. In the UK, we typically measure body weight in stone and pounds, though kilograms are also used in NHS health assessments. This guide explains how to calculate your weight, convert between different measurements, and find your healthy weight range using NHS guidance and free online tools.
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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.
How to Calculate Weight Using UK Measurements
Weight calculation in the UK involves understanding three main measurement systems: kilograms (kg), stone, and pounds (lbs). The conversion formulas are straightforward:
- Kilograms to stone: divide kg by 6.35 to get stone
- Kilograms to pounds: multiply kg by 2.2 to get lbs
- Stone to pounds: multiply stone by 14 to get pounds
For example, 70kg equals approximately 11 stone (or 154 lbs). However, rather than calculating manually, you can use our free weight converter above to instantly convert between any units. Most UK adults prefer stone for personal use, whilst the NHS uses kilograms for clinical records. Understanding which measurement to use depends on the context—your GP may refer to your weight in kg, but you might naturally think of yourself in stone and pounds.
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.
Finding Your Healthy Weight Range Using NHS Guidance
Once you know your weight, the next step is understanding whether it falls within a healthy range for your height. The NHS uses Body Mass Index (BMI) as the primary screening tool. A healthy BMI is between 18.5 and 24.9 according to NHS guidelines. To calculate your healthy weight range, you need your height in centimetres and your weight in kilograms. Use our free BMI calculator on this page to instantly check your personal BMI and see whether your weight falls within the healthy, overweight, or obese category. Remember that BMI is a screening tool only—it doesn't account for muscle mass or individual health variation. For personalised weight guidance tailored to your health conditions, always discuss your weight with your GP, who can provide NHS health advice specific to you.
- 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's the easiest way to calculate my weight in different units?
The easiest way is to use our free weight converter above, which instantly converts between kilograms, stone, and pounds. Simply enter your weight and it calculates all three units automatically. This avoids a UK pharmacy calculation errors and is much faster than working through formulas by hand.
How do I know if my calculated weight is healthy for my height?
Use your weight and height to calculate your BMI using our free BMI calculator on this page. The NHS defines a healthy BMI as 18.5–24.9. Your GP can also assess your weight in context of your individual health conditions, as healthy weight varies by person. For adults of South Asian or Black African heritage, lower BMI thresholds may apply according to NHS guidance.
What's the difference between stone and kilogram measurements in the UK?
Stone and pounds are traditional UK measurements, whilst kilograms are the metric standard used by the NHS clinically. One stone equals 6.35kg. Most UK adults use stone for personal weight tracking, but your GP will likely record your weight in kilograms in your medical records. Both are equally valid—it's just context-dependent.
Can I calculate a healthy weight range for my height?
Yes. A healthy weight range for your height can be calculated using BMI formulas. For example, if you're 1.73m tall, a healthy weight range is approximately 55–74kg (8st 8lbs to 11st 9lbs). Use our free BMI calculator above to find your personal healthy weight range based on your exact height and the NHS BMI thresholds.
Does calculating my weight tell me about my fitness or health status?
Weight calculation provides useful baseline information, but it's only one part of overall health. BMI doesn't distinguish between muscle and fat, and waist circumference also matters for health risk. Your GP can give you comprehensive weight management advice considering your full health picture, medical history, and individual circumstances.
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.