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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Convert 30 Litres to Kilograms
30 litres converts to approximately 30 kilograms for water, as 1 litre of water weighs roughly 1 kilogram. However, the conversion depends on the liquid's density — different liquids have different weights. This guide explains the litre to kilogram conversion, clarifies the relationship between volume and weight, and provides context for UK health and nutrition information. Understanding these measurements is helpful when tracking fluid intake or managing dietary information.
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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.
How to Convert Litres to Kilograms
The conversion from litres (a volume measurement) to kilograms (a weight measurement) depends entirely on the density of the liquid. For water, the relationship is straightforward: 1 litre of water weighs approximately 1 kilogram, so 30 litres of water equals roughly 30 kg.
- Water: 30 litres = ~30 kg (density of 1 g/ml)
- Milk: 30 litres = ~31 kg (slightly denser than water)
- Vegetable oil: 30 litres = ~27.6 kg (less dense than water)
- Honey: 30 litres = ~42 kg (much denser than water)
This is why litres and kilograms cannot be converted without knowing what substance you're measuring. In UK health guidance, daily fluid intake is measured in litres or millilitres, whilst body weight is measured in kilograms, stone, and pounds — they serve different purposes in nutrition and fitness tracking.
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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 Weight Converters for Health Management
If you're tracking your own weight as part of a health and fitness journey, use our free weight converter to switch between kilograms, stone, and pounds — the measurements you'll need for NHS health guidance and UK BMI calculators. For understanding fluid intake in the context of nutrition or hydration, remember that litres measure volume, not weight.
Our BMI calculator helps you assess whether you're in a healthy weight range according to NHS guidelines. Whether you're managing your weight independently or considering prescription weight management options like GLP-1 medication, accurate weight measurement in kilograms is essential for tracking progress and health outcomes.
- 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.
Can I convert litres to kilograms without knowing the liquid type?
No. Litres measure volume; kilograms measure weight. Without knowing the substance's density, you cannot accurately convert. For water, 1 litre ≈ 1 kg, but this does not apply to other liquids, oils, or solutions.
What is the density of water used in UK health calculations?
Water has a density of 1 gram per millilitre (g/ml) or 1 kilogram per litre (kg/l) at standard temperature and pressure. This makes the conversion simple for water: 30 litres = 30 kilograms. Other substances have different densities and convert differently.
How does this relate to daily fluid intake recommendations?
NHS guidance recommends approximately 6 to 8 glasses of water daily, roughly 1.5 to 2 litres. This is measured by volume (litres or millilitres), not weight. Body weight, tracked for BMI and health assessment, is measured in kilograms, stone, or pounds — separate measurements.
Should I use this conversion for tracking my body weight?
No. Your body weight should be measured using a bathroom scales that reads kilograms or stone directly. Use our free weight converter to switch between kg, stone, and pounds for UK health contexts like BMI calculation and NHS weight management guidance.
Why does honey weigh more than water at the same volume?
Honey is denser than water — it contains more mass in the same volume. Density varies by substance composition, temperature, and purity. This is why conversions between litres and kilograms must always account for the specific liquid being measured.
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.