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 is 42 kg in Stone?
42 kilograms converts to approximately 6 stone and 8 pounds (6st 8lbs) using the standard UK weight conversion. If you're checking your own weight or comparing measurements, our free weight converter above can help you switch between kg, stone, and lbs instantly. For adults, 42 kg is generally considered underweight according to NHS guidelines, though healthy weight ranges vary depending on your height and age. Understanding your weight in familiar UK measurements is the first step towards managing your health effectively.
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.
42 Kg Conversion and BMI Context
42 kg in stone and pounds:
- 42 kg = 6 stone 8.2 pounds (6st 8lbs)
- 42 kg = 92.6 pounds (92.6 lbs)
- Quick reference: divide kg by 6.35029 to get stone
Whether 42 kg is a healthy weight for you depends on your height. For example, if you're 1.55m (5ft 1in) tall, a weight of 42 kg gives you a BMI of approximately 17.5, which falls in the healthy weight range (18.5–24.9) according to NHS guidance. However, if you're significantly taller, this weight would likely fall below the healthy range. Our free BMI calculator on this page will show you your exact BMI category instantly. Remember that BMI is a screening tool but has limitations — it doesn't account for muscle mass or where fat is stored, so always discuss any health concerns with your GP.
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.
Is 42 Kg Healthy for Adults?
At 42 kg, you may be underweight, healthy, or overweight depending on your height — there's no single answer. The NHS uses BMI to assess healthy weight ranges, and for most adults, a BMI below 18.5 indicates underweight status, whilst 18.5–24.9 is the healthy range. If you're underweight, your GP may recommend checking your overall nutrition, energy levels, and general health. Conversely, if you're naturally lean or have a smaller frame, 42 kg may be perfectly appropriate for your height. Use our weight converter above to see your weight in different units, and use the BMI calculator to find your category. Your GP can provide personalised guidance based on your age, health history, and individual circumstances.
- 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 42 kg to stone?
Divide 42 by 6.35029 to get stone. 42 kg = 6 stone 8.2 pounds. You can use our free weight converter above to switch between kg, stone, and lbs instantly for any weight.
Is 42 kg a healthy weight?
It depends on your height. At 42 kg, you may be underweight, healthy, or overweight depending on how tall you are. Use our free BMI calculator to check your personal BMI category and healthy weight range.
What is 42 kg in pounds?
42 kg equals approximately 92.6 pounds (92.6 lbs). Multiply kg by 2.20462 to convert to pounds, or use our free weight converter for instant conversions.
Should I be concerned if I weigh 42 kg?
Not necessarily. If your BMI falls within the healthy range (18.5–24.9) for your height, your weight is likely appropriate. If you have any health concerns about your weight, discuss them with your GP.
What height matches 42 kg healthy weight?
A weight of 42 kg is healthy for adults approximately 1.52m to 1.62m tall (roughly 5ft 0in to 5ft 4in), depending on frame size and muscle mass. Taller or shorter adults would need different weights for a healthy BMI. Use the BMI calculator above to check your personal category.
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.