Use this LBS to KG Calculator to convert pounds into kilograms instantly. In the UK, kilograms are the standard for medical, clinical, and most everyday weight measurements — but pounds still appear in American recipes, US-based fitness apps, some gym equipment, and food products imported from the US. This tool bridges that gap.
LBS to KG Calculator
Convert pounds to kilograms instantly using the exact conversion formula: 1 lb = 0.45359237 kg.
Common LBS to KG Conversions
| Pounds | Kilograms |
|---|---|
| 1 lb | 0.45 kg |
| 2 lbs | 0.91 kg |
| 5 lbs | 2.27 kg |
| 10 lbs | 4.54 kg |
| 20 lbs | 9.07 kg |
| 50 lbs | 22.68 kg |
| 100 lbs | 45.36 kg |
| 120 lbs | 54.43 kg |
| 150 lbs | 68.04 kg |
| 180 lbs | 81.65 kg |
| 200 lbs | 90.72 kg |
| 250 lbs | 113.40 kg |
LBS to KG Formula
The internationally standardised conversion formula is:
Kilograms = Pounds × 0.45359237
For example: 150 lbs × 0.45359237 = 68.04 kg
Why UK Users Convert LBS to KG
The UK officially moved to metric weight (kilograms) decades ago. NHS records, GP appointments, BMI calculators, and pharmacy systems all use kilograms. However, pounds are still encountered regularly:
- American fitness content — YouTube workout programmes, US-based fitness apps (MyFitnessPal, Apple Health set to US defaults), and American personal trainers quote weight in lbs.
- US food and supplement labels — Protein powders, bulk foods, and supplements bought from American brands or imported via Amazon US display weights in lbs and oz.
- Some gym equipment — Older weight plates, some cable machines, and imported equipment may show lbs markings alongside or instead of kg.
- Birth weight — Many UK parents still record and discuss baby birth weight in pounds and ounces (e.g. “7 lbs 4 oz”), even though NHS records use grams and kilograms.
- US online shopping — Product listings on Amazon.com and other US retailers list shipping weights in pounds.
LBS to KG for NHS BMI and Medical Use
The NHS BMI calculator and GP records use kilograms for weight. If you know your weight in pounds — from an older scale, a US app, or a gym weigh-in — you’ll need to convert to kg before entering it into NHS tools or a BMI Calculator.
| Weight (lbs) | Weight (kg) | NHS BMI Context (5’7″ / 170cm) |
|---|---|---|
| 100 lbs | 45.4 kg | BMI ~15.7 — Underweight |
| 120 lbs | 54.4 kg | BMI ~18.9 — Healthy range |
| 140 lbs | 63.5 kg | BMI ~22.0 — Healthy range |
| 160 lbs | 72.6 kg | BMI ~25.1 — Overweight |
| 180 lbs | 81.6 kg | BMI ~28.2 — Overweight |
| 200 lbs | 90.7 kg | BMI ~31.4 — Obese (Class I) |
| 220 lbs | 99.8 kg | BMI ~34.5 — Obese (Class II) |
BMI figures above are illustrative for a person 170 cm tall. Use our BMI Calculator for your exact figures.
LBS to KG for UK Sports Weight Classes
UK combat sports — boxing, MMA, wrestling, powerlifting, and weightlifting — use kilograms for official weight classes. American fight promotions (UFC, WWE, Bellator) and US lifting federations typically use pounds. Here’s how the major weight classes convert:
Boxing Weight Classes (lbs → kg)
| Class Name | Limit (lbs) | Limit (kg) |
|---|---|---|
| Strawweight | 105 lbs | 47.6 kg |
| Light Flyweight | 108 lbs | 49.0 kg |
| Flyweight | 112 lbs | 50.8 kg |
| Featherweight | 126 lbs | 57.2 kg |
| Lightweight | 135 lbs | 61.2 kg |
| Welterweight | 147 lbs | 66.7 kg |
| Middleweight | 160 lbs | 72.6 kg |
| Light Heavyweight | 175 lbs | 79.4 kg |
| Heavyweight | 200 lbs | 90.7 kg |
| Super Heavyweight | 200+ lbs | 90.7+ kg |
UFC / MMA Weight Classes (lbs → kg)
| Class Name | Limit (lbs) | Limit (kg) |
|---|---|---|
| Strawweight | 115 lbs | 52.2 kg |
| Flyweight | 125 lbs | 56.7 kg |
| Bantamweight | 135 lbs | 61.2 kg |
| Featherweight | 145 lbs | 65.8 kg |
| Lightweight | 155 lbs | 70.3 kg |
| Welterweight | 170 lbs | 77.1 kg |
| Middleweight | 185 lbs | 83.9 kg |
| Light Heavyweight | 205 lbs | 93.0 kg |
| Heavyweight | 265 lbs | 120.2 kg |
LBS to KG for Baby Birth Weight
UK hospitals record newborn birth weight in grams (and kilograms), but many parents still communicate birth weight in pounds and ounces. If you need to convert for NHS records, health visitor forms, or a growth chart:
| Birth Weight (lbs & oz) | Kilograms | Notes |
|---|---|---|
| 5 lbs 8 oz | 2.50 kg | Low birth weight threshold (WHO) |
| 6 lbs 0 oz | 2.72 kg | Below average for UK |
| 7 lbs 0 oz | 3.18 kg | Near UK average |
| 7 lbs 8 oz | 3.40 kg | UK average birth weight |
| 8 lbs 0 oz | 3.63 kg | Above average |
| 9 lbs 0 oz | 4.08 kg | Large baby |
| 10 lbs 0 oz | 4.54 kg | Very large — top ~5% UK |
To convert pounds and ounces: first convert ounces to a decimal (divide oz by 16), add to lbs, then multiply by 0.45359237.
LBS to KG Conversion Table
| Pounds | Kilograms |
|---|---|
| 1 lb | 0.45 kg |
| 5 lbs | 2.27 kg |
| 10 lbs | 4.54 kg |
| 20 lbs | 9.07 kg |
| 30 lbs | 13.61 kg |
| 50 lbs | 22.68 kg |
| 100 lbs | 45.36 kg |
| 120 lbs | 54.43 kg |
| 140 lbs | 63.50 kg |
| 150 lbs | 68.04 kg |
| 160 lbs | 72.57 kg |
| 180 lbs | 81.65 kg |
| 200 lbs | 90.72 kg |
| 220 lbs | 99.79 kg |
| 250 lbs | 113.40 kg |
Frequently Asked Questions
How do I convert lbs to kg?
Multiply the pounds value by 0.45359237. For example: 150 lbs × 0.45359237 = 68.04 kg.
Does the NHS use pounds or kilograms?
The NHS uses kilograms for adult and child weight in medical records, BMI calculations, and drug dosing. If your scale shows pounds, convert to kg before entering your weight into NHS online tools.
What is 7 lbs 4 oz in kg?
7 lbs 4 oz = 7.25 lbs. Multiply by 0.45359237 = 3.29 kg. A common birth weight, approximately the UK average.
What is 150 lbs in kg?
150 lbs = 68.04 kg. This is close to the Welterweight boxing limit (66.7 kg).
What is 200 lbs in kg?
200 lbs = 90.72 kg. This is approximately the Heavyweight boxing limit (90.7 kg).
Is pounds bigger than kilograms?
No. One kilogram is heavier than one pound. 1 kg = approximately 2.205 lbs. So when you convert lbs to kg, the number becomes smaller.
Related Calculators
- KG to LBS Calculator — Convert kilograms into pounds
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- Ideal Weight Calculator — Find a healthy weight range for your height
- Calorie Calculator — Estimate daily calorie needs
- CM to Inches Calculator — Convert centimetres to inches