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
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What Is HR For Weight Loss And How Does It Work?
HR (heart rate) is a practical tool for weight management because it helps you exercise at the right intensity for fat burning. When you're losing weight in the UK, understanding your heart rate zones allows you to maximise calorie burn during workouts and track your cardiovascular progress. Combined with a calorie deficit from dietary changes, targeting specific heart rate zones can support sustainable weight loss alongside lifestyle modifications. Our free BMI calculator helps you understand your baseline health status, whilst monitoring HR during exercise gives you real-time feedback on workout intensity.
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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.
Heart Rate Zones And Fat Burning
Your target heart rate zone depends on your age, resting heart rate, and fitness level. The most effective HR zone for weight loss is typically 50–70% of your maximum heart rate, known as the aerobic or fat-burning zone. In this zone, your body primarily uses fat for fuel rather than carbohydrates, making it ideal for sustainable weight management.
- Moderate intensity (50–70% max HR): Burns fat efficiently, sustainable for longer duration
- Vigorous intensity (70–85% max HR): Higher calorie burn, but harder to maintain and more demanding
- Low intensity (below 50% max HR): Warm-up and recovery, limited weight loss benefit
To calculate your approximate maximum heart rate, subtract your age from 220. For example, a 40-year-old has an estimated max HR of 180 bpm. Their fat-burning zone would be 90–126 bpm (50–70% of 180). Monitoring your HR during exercise using a fitness tracker or chest strap ensures you stay in the right zone for your weight loss goals.
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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.
Using HR Monitoring For Sustainable Weight Management
Heart rate monitoring works best when combined with a calorie deficit and consistent exercise routine. Weight loss requires burning more calories than you consume, and exercising in the right HR zone helps maximise fat utilisation during workouts. The NHS recommends at least 150 minutes of moderate-intensity aerobic activity per week, which often aligns perfectly with fat-burning heart rate zones.
Many people find that tracking both HR and weight loss progress together provides motivation and accountability. Use our free progress tracker to log your workouts, weight changes, and energy levels over time. This data helps you see the relationship between consistent exercise at appropriate intensity and gradual, sustainable weight loss. Remember that weight loss is a combination of exercise, nutrition, and lifestyle — HR monitoring is one helpful tool, not a complete solution on its own.
- 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 is the best heart rate zone for weight loss?
The fat-burning zone is typically 50–70% of your maximum heart rate. This intensity allows your body to use fat as primary fuel. Calculate your max HR by subtracting your age from 220, then multiply by 0.5 and 0.7 to find your zone range. Exercising consistently in this zone supports sustainable weight loss when combined with a calorie deficit.
How do I calculate my target heart rate for weight loss?
Subtract your age from 220 to estimate maximum heart rate. Multiply that number by 0.5 for the lower bound and 0.7 for the upper bound of your fat-burning zone. For example, a 35-year-old has max HR of 185; their fat-burning zone is 92–130 bpm. Use a fitness tracker or chest strap to monitor during exercise.
Can heart rate monitoring alone help me lose weight?
No — HR monitoring is a tool to optimise exercise intensity, but weight loss requires a calorie deficit overall. You need to burn more calories than you consume through a combination of exercise and dietary changes. HR helps ensure your workouts are effective, but diet remains equally important for sustainable weight loss.
How often should I monitor my heart rate for weight loss?
Aim to exercise in your target HR zone at least 3–5 times per week for 20–30 minutes per session, following NHS recommendations. Consistency matters more than frequency. Track your HR during each workout using a fitness tracker, and log your progress with our free progress tracker to see weight loss results over weeks and months.
Should I combine HR monitoring with other weight loss methods?
Yes — HR monitoring works best alongside a balanced diet, calorie deficit, and consistent physical activity. Some people also benefit from formal weight loss programmes or prescription support. If you have a BMI over 30 or significant weight-related health concerns, your GP can discuss all available weight management options in the UK, including lifestyle changes and medical support.
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.