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 Effective Is Swimming for Weight Loss?
Swimming is one of the most effective forms of physical activity for weight loss. It burns considerable calories, builds muscle, and is low-impact, making it sustainable for most people. Combined with a reduced-calorie diet and healthy lifestyle changes, swimming can contribute meaningfully to weight management. However, weight loss depends on multiple factors including diet, overall activity level, and individual metabolism. Our free BMI calculator can help you track where you stand, and understanding your starting point is key to setting realistic weight loss goals.
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 Many Calories Does Swimming Burn?
The number of calories burned during swimming varies significantly based on stroke type, intensity, duration, and body weight. A person weighing 70 kg (11 stone) swimming at moderate intensity for 30 minutes typically burns 200–300 calories. More vigorous swimming (front crawl at fast pace) can burn 400–500+ calories in the same timeframe. Breaststroke is gentler and burns fewer calories, whilst backstroke and butterfly are more demanding. Swimming for 60 minutes at moderate intensity most days of the week, combined with a calorie deficit, can support steady weight loss of approximately 0.5–1 kg per week — which aligns with NHS guidance for sustainable weight loss. Water resistance also builds lean muscle, which increases your resting metabolic rate over time.
Clinically BackedWeight Loss
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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.
Swimming vs Other Forms of Exercise for Weight Loss
Swimming is particularly effective because it engages multiple muscle groups simultaneously, is low-impact (reducing joint stress), and can be sustained for longer periods than high-impact activities like running. For people with joint problems, excess weight, or those returning to exercise, swimming is often the preferred starting point. However, weight loss ultimately depends on consistent calorie deficit — swimming alone, without dietary changes, may not produce significant results. Combining regular swimming with healthy eating and tracking progress through tools like our free progress tracker helps maintain consistency and motivation over time.
- 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 swim to lose weight?
For meaningful weight loss, aim for 3–5 swimming sessions per week, each lasting 30–60 minutes. Consistency matters more than intensity. Combine swimming with a balanced diet to create a calorie deficit. Your GP can advise on a safe exercise plan tailored to your health.
Can swimming alone help me lose weight without changing my diet?
Swimming burns calories and builds fitness, but weight loss requires a calorie deficit. Diet changes are usually essential. The NHS recommends combining physical activity with a reduced-calorie balanced diet for sustainable results. Most people need both to see meaningful change.
Is swimming better than running for weight loss?
Swimming burns similar calories to running but is lower-impact, making it more sustainable long-term for many people. Choose the activity you'll stick with consistently. Both are effective when combined with a healthy diet and calorie deficit.
What if I need additional support for weight loss?
If diet and exercise alone aren't delivering results, your GP can discuss additional options. For adults with a BMI of 30 or above, or 27+ with weight-related health conditions, prescription weight loss medication may be appropriate. These are used alongside lifestyle changes, not instead of them.
How do I track my swimming progress for weight loss?
Log your swimming sessions (frequency, duration, intensity) and weekly weight in our free progress tracker. This helps identify patterns and keeps you motivated. Also calculate your BMI regularly to see health improvements alongside weight changes.
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.