Weight Converter
This weight converter lets you move seamlessly between metric and imperial units so you can quote exact numbers in any conversation.
Headline conversion
1
Kilogram (kg)
2.2
Pound (lb)
All supported units
Compare every available unit at a glance; values refresh when you adjust the input or swap units.
Unit
Kilogram (kg)
Value
1
Unit
Gram (g)
Value
1,000
Unit
Milligram (mg)
Value
1,000,000
Unit
Metric ton (t)
Value
0
Unit
Pound (lb)
Value
2.2
Unit
Ounce (oz)
Value
35.27
Unit
Stone (st)
Value
0.16
Locale preference: en-US. Use the swap button to reverse the conversions instantly.
Tool Overview
The Weight Conversion Calculator is an essential tool for navigating the US Imperial system and the Metric system used by the rest of the world.
In the US, we use pounds (lbs) and ounces (oz) for almost everything grocery shopping, body weight, and postal packages. However, science, medicine, and international trade rely on kilograms (kg) and grams (g).
This tool bridges that gap instantly. Whether you are following a European recipe, tracking your weight for a medical chart, or shipping a package overseas, you can get precise conversions without the mental math.
Key features include:
Simple Interface: Just type and see results.
All-in-One Grid: See your value converted to every unit simultaneously.
Decimal Precision: crucial for medication dosages or baking formulations.
How to Use This Calculator
Converting between Imperial and Metric is straightforward.
- 1
Select Input Unit
Choose the unit you know (e.g., 'Pounds' if you weighed yourself on a US scale).
- 2
Enter Weight
Type the number. For example, '150'.
- 3
Select Output Unit
Choose the unit you need (e.g., 'Kilograms' for a medical form).
- 4
View Result
The result appears instantly. 150 lbs = ~68 kg.
Key Terms & Definitions
The Math Behind the Conversion
We use standard international conversion factors:
1 kg = 2.20462 lbs
1 lb = 453.592 grams
1 oz = 28.3495 grams
When you enter a value, we first convert it to a base unit (grams) and then calculate all other values from there. This minimizes rounding errors.
Real-World Scenarios
Baking & Cooking
European recipes list flour in grams. US recipes use cups or ounces. A kitchen scale and this tool make following Gordon Ramsay's recipes possible.
Medical Charts
US doctors record weight in lbs, but medication dosages are often calculated in mg per kg of body weight. Parents can use this to understand pediatric doses.
Gym & Powerlifting
Olympic plates and competitions use kilograms. A '100kg lift' sounds different than '220 lbs', but they are the same bench press.
Travel & Luggage
US airlines limit bags to 50 lbs. International carriers often limit them to 23 kg. Before you fly, check if 23 kg < 50 lbs (It is: 23kg is 50.7 lbs).
Common Mistakes
Confusing Ounces and Fluid Ounces
An 'ounce' (weight) is not the same as a 'fluid ounce' (volume). 8 oz of flour does NOT fill an 8 fl oz measuring cup. Always use a scale for dry ingredients.
Rounding Errors
Approximating 1 kg as 2 lbs works for lifting weights, but fails for baking or chemistry. 1 kg is actually 2.2 lbs.
Assumptions
We assume standard earth gravity.
We use the International Avoirdupois pound definition.
Frequently Asked Questions FAQs
There are approximately 2.20462 pounds in one kilogram.
The US doesn't use 'Stone' officially. In the UK, a Stone is exactly 14 pounds. This calculator uses that standard definition.
The medical field uses the metric system universally to avoid errors. Dosing by body weight (mg/kg) provides the safest, most effective reference.
Most international economy flights limit checked bags to 23 kg (50 lbs). Domestic US flights typically use the 50 lbs limit directly.