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 to Use a Weight Tracker for Health Management
A weight tracker is a simple but powerful tool for monitoring your body weight over time and understanding your health progress. Whether you're managing weight for general health, working towards a healthy weight range, or supporting weight management through lifestyle changes or medication, tracking provides valuable insight into trends and patterns. Regular monitoring helps you stay motivated, identify what works for your body, and make informed decisions with your GP or healthcare team. MyWeightCheck's free progress tracker makes logging your weight straightforward and helps you visualise your journey with clear, easy-to-read data.
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.
Why Consistent Weight Tracking Matters
Tracking your weight regularly—ideally weekly at the same time of day—helps you spot meaningful patterns beyond daily fluctuations. Weight naturally varies day to day due to hydration, salt intake, hormones, and digestion, so weekly or fortnightly tracking smooths out these variations and shows your true progress. NHS guidance emphasises that sustainable weight management combines healthy eating, physical activity, and monitoring—tracking keeps you aware and accountable without obsessing over single daily changes.
- Weekly weigh-ins provide clearer trends than daily measurements
- Tracking supports behaviour change by making progress visible
- Records help you and your GP identify what's working for your individual health
- Consistency matters more than perfection—missed weigh-ins don't derail progress
If you're using our free weight converter or BMI calculator alongside your progress tracker, you can also monitor how your BMI changes as you lose weight, adding another layer of useful context to your health journey.
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.
Getting Started With Weight Tracking
Begin by weighing yourself weekly—Tuesday or Wednesday mornings are popular choices to avoid weekend variations. Record your weight in the units you're most comfortable with—whether that's kilograms, stone, or pounds. Our free progress tracker stores all your entries and displays them in a simple graph so you can see trends at a glance. You don't need an expensive scale; any reliable household scale works fine. Set realistic expectations: healthy, sustainable weight loss averages 0.5–1 kg per week according to NHS guidance. If you're starting weight management medication like Mounjaro or Wegovy, a progress tracker becomes even more valuable for documenting how you respond over the weeks and months ahead.
- 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 often should I weigh myself when tracking progress?
Aim for once weekly at the same time of day for most accurate tracking. Weekly measurement smooths out daily water and food fluctuations and gives you a clearer picture of real progress. If you're taking weight loss medication, consistent weekly tracking helps you and your prescriber assess how you're responding.
Why does my weight fluctuate so much day to day?
Daily weight changes are normal and usually due to hydration, salt intake, hormones, digestion, and exercise recovery—not actual fat loss or gain. Weekly tracking removes these daily noise and reveals genuine trends. This is why NHS guidance recommends weekly, not daily, weighing for most people.
What weight should I aim for according to NHS guidance?
A healthy BMI is 18.5–24.9 for most adults, though thresholds are lower for people of South Asian, Chinese, or Black African and Caribbean heritage. Use our free BMI calculator with your current weight and height to find your healthy weight range, then use your tracker to monitor progress towards that goal.
How does tracking help if I'm using weight loss medication?
Regular tracking documents your response to medications like Mounjaro or Wegovy and helps your prescriber adjust doses if needed. It also motivates you by making progress visible and supports the lifestyle changes that medications work best alongside.
Can I use a weight tracker if I'm also trying to build muscle?
Yes—tracking weight alone has limitations if you're exercising heavily, as muscle weighs more than fat. However, combined with how your clothes fit, energy levels, and our free progress tracker, weekly weight data still provides useful context about overall health progress.
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.