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 BMI Is 108 Lbs in Kg?
108 lbs converts to approximately 49 kg. However, BMI depends on both weight and height, so the same weight gives very different BMI values depending on how tall you are. Below we show what BMI 49 kg produces at different heights, using NHS categories. Use our free BMI calculator above to find your exact BMI instantly by entering your height and weight together.
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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 49 kg (108 lbs) — Different Heights
At 49 kg (108 lbs), your BMI depends entirely on your height. Here are six common examples:
- 5ft 0in (152 cm): BMI 21.3 — healthy weight
- 5ft 4in (163 cm): BMI 18.5 — healthy weight (lower boundary)
- 5ft 6in (168 cm): BMI 17.7 — underweight
- 5ft 8in (173 cm): BMI 16.4 — underweight
- 5ft 10in (178 cm): BMI 15.5 — underweight
- 6ft 0in (183 cm): BMI 14.6 — underweight
If you're significantly taller than 5ft 4in, 49 kg typically falls below the healthy weight range. Conversely, if you're shorter, it may fall comfortably within a healthy BMI. Convert your weight using our weight converter to see 49 kg expressed in stone and pounds (7st 10lbs), which many UK adults find easier to relate to.
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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.
NHS BMI Categories and Limitations
The NHS uses these BMI categories for adults: underweight (below 18.5), healthy weight (18.5–24.9), overweight (25.0–29.9), obese class I (30.0–34.9), and obese class II or higher (35.0+). However, BMI has important limitations. It does not distinguish between muscle and fat — athletes may have a high BMI but low body fat. BMI also ignores where fat is stored; waist circumference matters for health. For South Asian, Chinese, Black African, and Black Caribbean adults, the NHS recommends lower BMI thresholds because these groups face higher health risks at the same BMI level. Always discuss your personal healthy weight range with your GP.
- 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 108 lbs a healthy weight?
Whether 108 lbs (49 kg) is healthy depends on your height. For someone 5ft 4in, it's near the healthy boundary. For someone taller than 5ft 8in, it's likely underweight. For someone shorter than 5ft 2in, it may be comfortable. Use our BMI calculator to check your personal situation.
What is 108 lbs in stone and pounds?
108 lbs equals 7 stone and 10 pounds (7st 10lbs). To convert between metric and imperial weight, divide lbs by 14 to get stone, or use our free weight converter above for gradual improvement in both systems.
How do I know my healthy weight range?
Your healthy weight range depends on your height and sex. The NHS BMI calculator defines healthy weight as a BMI between 18.5 and 24.9. For South Asian, Chinese, Black African, or Black Caribbean adults, the range is 18.5–22.9. Your GP can provide personalised guidance based on your individual health.
Why does BMI vary so much with height?
BMI uses the formula weight (kg) divided by height (metres) squared. Even small height differences create large BMI changes because height is squared in the equation. This is why BMI at a fixed weight like 49 kg spans underweight to healthy depending on whether you're 5ft 0in or 6ft 0in tall.
Does BMI tell the whole story about health?
No. BMI is a useful screening tool but doesn't account for muscle mass, fat distribution, or where fat is stored around the body. Waist circumference and overall fitness matter too. Your GP can assess your health holistically rather than BMI alone.
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.