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 a Weighted Calculator and How Does It Help?
A weighted calculator is a health tool that helps you understand your weight in relation to your height, age, and other health factors. In the UK, the most common weighted approach uses BMI (Body Mass Index) calculations alongside NHS health guidance. Unlike a simple weight converter, a weighted calculator factors in your height and provides health context — helping you see whether your current weight falls in a healthy range for your individual measurements. MyWeightCheck offers free weighted assessment tools to help you track your health status.
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 Weighted Calculators Work in UK Health Guidance
A weighted calculator typically combines weight and height measurements to determine your BMI and health category according to NHS standards. The calculation is simple: your weight in kilograms divided by your height in metres squared. However, the real value of a weighted calculator is what comes next — it tells you whether your result falls into healthy weight, overweight, or obese ranges.
- Standard BMI categories (NHS): Healthy weight 18.5–24.9, Overweight 25–29.9, Obese 30+
- For South Asian, Chinese, Black African, or Black Caribbean adults: lower thresholds apply (healthy weight 18.5–22.9)
- A weighted calculator also considers that individual results vary — muscle, bone density, and body composition all affect your true health status
- Our free BMI calculator on this page instantly shows your category and healthy weight range for your height
Unlike a simple weight converter that just changes kg to stone, a weighted calculator provides NHS health context — showing you what your weight means for your wellbeing.
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.
Why Use a Weighted Calculator vs. Just Converting Weight?
A weight converter only tells you what your weight is in different units — for example, that 70kg equals 11 stone. A weighted calculator goes further, showing whether that weight is healthy for your specific height and age. For instance, 70kg might be a healthy weight for someone 1.80m tall, but concerning for someone 1.55m tall.
Using our weight converter and BMI calculator together gives you complete picture. You can convert between kg, stone, and pounds, then instantly see your BMI category and healthy weight range according to UK health standards. This combined approach helps you understand not just what you weigh, but whether that weight supports your health — which is what the NHS weight management pathway focuses on.
- 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 a weighted calculator the same as a BMI calculator?
Not quite. A BMI calculator is one type of weighted calculator — it uses weight and height together. However, weighted calculators can also include other factors like age, ethnicity, and waist circumference. BMI is the most common UK weighted measure because the NHS uses it for health screening. Our free BMI calculator is the quickest way to get your weighted health category.
Can a weighted calculator tell me if I need weight loss medication?
A weighted calculator shows whether your BMI meets NHS eligibility criteria for weight management support (BMI 30+, or 27+ with health conditions). However, only a GP or licensed prescriber can assess whether prescription medication like Mounjaro or Wegovy is appropriate for you. Your calculator result is the starting point — clinical assessment is essential.
Why do South Asian adults need different weighted thresholds?
Research shows that South Asian, Chinese, Black African, and Black Caribbean adults face higher cardiovascular and diabetes risk at lower BMI levels than other populations. The NHS therefore recommends lower healthy weight thresholds (18.5–22.9 instead of 18.5–24.9) for these groups. A weighted calculator that includes ethnicity gives more accurate health context.
What's the difference between a weighted calculator and a weight loss calculator?
A weighted calculator shows your current health status — where your weight sits relative to healthy ranges. A weight loss calculator (like our GLP-1 weight loss calculator) projects how much weight you might lose with medication or lifestyle changes. Use the weighted calculator first to understand your starting point, then explore weight loss options if needed.
Should I trust a weighted calculator more than my GP's assessment?
A weighted calculator is a useful screening tool and starting point for conversation, but it has limitations — it doesn't account for muscle mass, bone density, or individual health factors. Always discuss your results with your GP, who can provide personalised health advice beyond what any calculator can show. Our tools are educational aids, not medical diagnoses.
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.