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's 138 Kg in Pounds and What Does It Mean for Your BMI?
138 kilograms equals approximately 304 pounds (or 21 stone 12 pounds in UK measurements). However, your BMI depends entirely on your height — the same weight can be healthy for a tall person but indicate overweight or obesity for someone shorter. Using our free BMI calculator above, you can instantly discover your personal BMI at this weight and see which NHS health category you fall into. This guide shows BMI examples at different heights so you can understand what 138 kg means for your individual health.
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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.
BMI at 138 Kg for Different Heights
At 138 kg, your BMI varies significantly depending on your height. Here are realistic examples:
- 5ft 4in (163 cm): BMI 23.0 — Healthy weight range (18.5–24.9)
- 5ft 6in (168 cm): BMI 22.3 — Healthy weight range
- 5ft 8in (173 cm): BMI 21.6 — Healthy weight range
- 5ft 10in (178 cm): BMI 20.9 — Healthy weight range
- 6ft 0in (183 cm): BMI 20.4 — Healthy weight range
- 6ft 2in (188 cm): BMI 19.6 — Healthy weight range
As you can see, at 138 kg this weight is in the healthy range for adults of average to tall height. However, for shorter adults, 138 kg may fall into the overweight category. Use the weight converter and BMI calculator on this page to check your exact position.
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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.
Understanding Your BMI Category and NHS Guidelines
The NHS uses these BMI categories for UK adults: healthy weight is 18.5–24.9, overweight is 25.0–29.9, and obese is 30.0 and above. It's important to remember that BMI is a screening tool only — it doesn't account for muscle mass, bone density, or where fat is stored on your body. A person with significant muscle may have a higher BMI but excellent health. Your GP can provide personalised health advice based on your weight, medical history, and lifestyle. If you're concerned about your weight or health, speak with your GP who can assess your individual situation and discuss any health risks or benefits of weight management.
- 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 do I convert 138 kg to pounds?
138 kg equals 304.2 pounds (or 21 stone 12 pounds in UK measurements). You can use our free weight converter on this page to switch instantly between kilograms, pounds, and stone — the conversion is straightforward: 1 kg = 2.20462 pounds.
Is 138 kg a healthy weight?
It depends entirely on your height. At 138 kg, taller adults (5ft 8in and above) typically fall into the healthy BMI range, while shorter adults may be overweight. Use the BMI calculator above with your height to find your personal BMI and NHS category.
What are the NHS BMI categories?
The NHS defines healthy BMI as 18.5–24.9, overweight as 25.0–29.9, obese as 30.0–34.9, and severely obese as 40.0 and above. However, BMI has limitations — it doesn't distinguish between muscle and fat. Your GP can give you full context on what your BMI means for your health.
What if my BMI at 138 kg is overweight or obese?
If you're concerned about your weight or health, speak with your GP. They can assess your individual health risks and discuss sustainable approaches to weight management, which might include lifestyle changes, diet, exercise, or in some cases, prescription treatments — all tailored to you.
Why does the same weight give different BMIs at different heights?
BMI measures weight relative to height squared. Taller people have more body surface area, so their weight is distributed differently. This is why the same weight (138 kg) is healthy for someone 6ft tall but may indicate overweight for someone 5ft 2in.
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.