Pounds to Kg Converter
Convert pounds to kg in one step for formal documents, postal forms, medical records, and cookbook recipes. Type a pound value and read the exact kilogram result, then swap to run the reverse kg to pounds conversion. The same lbs to kg tool covers household weights, postal limits, common bodyweight values, and cooking quantities.
1 Pound = 0.453592 Kilogram
Pounds to kilograms reference table
Everyday weights between 1 and 100 pounds, with the kilogram value and a familiar item for context.
| Pounds | Kilograms | Context |
|---|---|---|
| 1 lb | 0.45 kg | Bag of sugar, small package |
| 2 lb | 0.91 kg | Standard letter paper ream |
| 5 lb | 2.27 kg | Bag of flour |
| 10 lb | 4.54 kg | Dumbbell, sack of potatoes |
| 15 lb | 6.80 kg | Bowling ball |
| 20 lb | 9.07 kg | Average house cat |
| 25 lb | 11.34 kg | Carry-on luggage limit (many airlines) |
| 50 lb | 22.68 kg | Bag of dog food, sand |
| 70 lb | 31.75 kg | Airline max checked bag (IATA) |
| 100 lb | 45.36 kg | Heavy shipping item |
Cooking ingredient conversion (pounds to grams)
Recipes that list ingredients in pounds, converted to grams for use with a metric kitchen scale.
| Quantity | Decimal pounds | Butter | Flour | Sugar |
|---|---|---|---|---|
| 1/4 lb | 0.25 lb | 113 g | 113 g | 113 g |
| 1/2 lb | 0.50 lb | 227 g | 227 g | 227 g |
| 3/4 lb | 0.75 lb | 340 g | 340 g | 340 g |
| 1 lb | 1.00 lb | 454 g | 454 g | 454 g |
| 2 lb | 2.00 lb | 907 g | 907 g | 907 g |
Note: a pound weighs the same regardless of the ingredient. The columns above show identical gram values to make recipe lookups quick.
Why use this converter
Document-ready precision
Results to multiple decimal places, suitable for formal forms, lab reports, and customs declarations.
Household reference table
Common postal and household weights from 1 pound to 100 pounds, with real-world context.
Recipe converter
Convert pound-based cookbook quantities into kilograms and grams for metric kitchen scales.
Formal vs informal spelling
Designed for users who write "pounds" in full on official documents, not just gym shorthand.
No tracking, no signup
Open the page, type your value, copy the result. Nothing is stored.
Works offline once loaded
After the first load, the conversion still runs without a connection in your browser.
When you need pounds to kg conversion
Customs declarations
International shipping forms ask for weight in kilograms even when your scale reads in pounds. Convert before filling in the value to avoid customs delays.
Postal and courier forms
Many global postal services and couriers require the parcel weight in kilograms. A 25 pound box is 11.34 kg.
Medical patient records
US clinics record body weight in pounds, but medication dosing is calculated per kilogram. Both values are written on the chart.
Cookbook ingredient lists
Older US and British cookbooks use pounds for meat, flour, and butter. Convert to grams or kilograms for metric kitchen scales.
Scientific lab reports
Lab notebooks and published papers use SI units. When sourcing material described in pounds, convert before recording the figure.
International health certificates
Veterinary import permits and travel health forms request animal or patient weights in kilograms. Convert pound figures before submission.
About pounds and kilograms
The pounds to kilograms formula
One international avoirdupois pound is defined as exactly 0.45359237 kilograms. To convert pounds to kg, multiply your pound value by 0.45359237. So 12 pounds becomes 5.44 kilograms, and 50 pounds becomes 22.68 kilograms. To go the other way, divide the kilogram figure by 0.45359237 (or multiply by 2.20462). The fixed conversion factor was set by an international agreement in 1959, which standardised the pound across the United States, the United Kingdom, Canada, Australia, New Zealand, and South Africa. Before that, different countries used slightly different pound values, which caused real problems for international trade.
Lbs to kg: the same conversion, a different label
Searches for lbs to kg and pounds to kg ask for exactly the same thing. "Lbs" and "lb" are simply the abbreviated forms of "pounds", so an lbs to kg conversion uses the identical factor of 0.45359237. The "lb" abbreviation comes from the Latin word libra, which is why it looks unrelated to the English spelling. Whether a form, scale, or recipe uses "pounds", "lb", or "lbs", you can enter the number into the converter above and read the kilogram result without any change in method.
A rounded factor for quick estimates
For mental math and rough planning, many people use a rounded pounds to kilograms factor instead of the exact 0.45359237. Multiplying by 0.45, or simply dividing by 2.2, gets you close enough for grocery shopping or packing a bag. For example, 100 pounds divided by 2.2 is about 45.5 kg, very near the exact 45.36 kg. Use the rounded factor for everyday estimates, but rely on the calculator above whenever a document, customs form, or medical record needs the precise value.
Etymology: where the word "pound" comes from
The English word "pound" descends from the Latin "libra pondo", a Roman expression meaning "a pound by weight". Over the centuries the phrase was shortened in different ways across Europe. English kept the second word and turned "pondo" into "pound". The abbreviation "lb", however, kept the first word, the Latin "libra". That is why the abbreviation looks unrelated to the English spelling. The same Latin root also gave us the British currency symbol, written with a stylised "L" for libra. So the words "pound", "lb", and the British pound sign all share one common Latin ancestor, even though they now refer to different things in modern English.
Pounds vs pound sterling: avoiding confusion
"Pounds" can mean two completely different things depending on context. The pound as a weight unit is a measurement, abbreviated "lb" or "lbs", and equal to 0.45359237 kilograms. The pound sterling is the official currency of the United Kingdom, abbreviated GBP, and written with the pound sign. They share a name because the British currency was originally based on a literal pound weight of silver, but the two meanings have not been linked for centuries. When reading a document, check the surrounding context. A shipping invoice that says "weight: 12 pounds" is talking about mass. A price tag that says "12 pounds" is talking about money. International forms sometimes label the unit explicitly to remove any doubt, writing "12 lb" for weight or "12 GBP" for currency.
Pounds on customs declarations and shipping forms
When you ship a parcel internationally from the United States, the shipping label and customs declaration usually require the weight in both pounds and kilograms. The carrier needs the kilogram value for handling in destination countries that use the metric system, and the pound value matches what the sender weighs on a US scale. A 5 pound package is 2.27 kg, a 10 pound package is 4.54 kg, and a 25 pound package is 11.34 kg. Most international postal services apply weight breaks at round kilogram values (1 kg, 2 kg, 5 kg, 10 kg), so a parcel that weighs 11.10 lb (5.03 kg) may fall into a more expensive bracket than one at 11.00 lb (4.99 kg). Knowing the exact kilogram figure helps you avoid surprise postage charges. The Universal Postal Union sets a general parcel weight limit of 30 kg (66.1 pounds), though individual destinations can set lower limits.
Pounds in medical patient records
In the United States, body weight on a medical chart is typically recorded in pounds because that is what the clinic scale displays. But medication dosing is almost always calculated per kilogram of body weight, so the kilogram value is also noted. A patient who weighs 154 pounds is 70 kg, a common adult reference weight. Pediatric medicine relies heavily on accurate kilogram weights, since a child who weighs 22 pounds (10 kg) receives a much smaller dose than an adult of the same medication. International health certificates, vaccination records, and travel medical forms generally request weight in kilograms even when the patient is American. Converting before filling the form prevents clerical errors that can affect dosing or insurance billing.
Pounds in cookbook recipes
US cookbooks list meat, flour, butter, and bulk produce in pounds, and older British cookbooks do the same. A recipe that calls for "one pound of ground beef" needs 454 grams of mince when shopping in a metric supermarket. Half a pound of butter is 227 grams, which is roughly two standard 113 gram sticks. When scaling a US recipe up or down, working in grams is usually easier than juggling fractions of a pound, since grams give whole-number results for any portion size. The reference table above lists the most common cookbook quantities in grams for quick lookups without a calculator.
How to estimate pounds to kilograms in your head
A quick mental method is to divide the pound value by two and then subtract about ten percent of the result. So 20 pounds: half is 10, subtract one to get 9 kilograms (exact value 9.07 kg). Or 50 pounds: half is 25, subtract 2.5 to get 22.5 kg (exact 22.68 kg). The estimate is accurate to about one percent, which is plenty for grocery shopping or rough planning. For documents, customs forms, and medical records, always use the calculator above and write down the exact value rather than the mental shortcut.
Common bodyweight conversions
One of the most frequent reasons people convert pounds to kg is to read a bodyweight figure in metric. A few worked examples cover the most searched values: 140 lbs is 63.50 kg, 150 lbs is 68.04 kg, 160 lbs is 72.57 kg, and 200 lbs is 90.72 kg. To find any of these yourself, just multiply the pound figure by 0.45359237. These conversions are useful for BMI calculations, fitness tracking, and medical forms that record weight in kilograms even when the patient stepped on a scale marked in pounds.
Pounds and stones for UK readers
In the United Kingdom and Ireland, bodyweight is often given in stones and pounds rather than a plain pound figure. One stone equals 14 pounds, so a weight written as "11 stone 4 pounds" is 158 pounds in total, which converts to about 71.67 kg. To convert a stones-and-pounds figure, first turn it into total pounds (multiply the stones by 14 and add the leftover pounds), then multiply by 0.45359237. This two-step approach lets the same pounds to kg converter handle UK-style weights without any special mode.
Converting kilograms back to pounds
The reverse conversion, kg to pounds, divides the kilogram value by 0.45359237, which is the same as multiplying by 2.20462. So 70 kg is about 154.3 pounds, and 5 kg is about 11.02 pounds. The converter on this page handles both directions: enter a pound value to get kilograms, or use the swap control to enter a kilogram value and read the pound result. Because the factor is fixed and exact, the round trip from pounds to kilograms and back returns the original number.
Why the spelling matters
On formal documents, technical writing, and recipe books, the unit is spelled out in full as "pounds". The abbreviation "lbs" is more common in casual contexts such as gym posters, sports broadcasts, and product packaging where space is tight. Both refer to the same weight unit, so you can use either when you write down the conversion. If you are completing a customs form, a shipping label, or a medical document, follow the convention printed on the form itself. Most international forms accept either "pounds" or "lbs" as long as the number is clear.
They refer to the same unit of weight. "Pounds" is the full English word, while "lbs" is the written abbreviation taken from the Latin word "libra" (meaning scales or balance). On formal documents, scientific papers, customs forms, and cookbooks, the word is often spelled out as "pounds" to avoid confusion. In casual gym or sports settings, "lbs" is the common shorthand.
Multiply the pound value by 0.45359237. For a quick rough estimate, multiply by 0.45 or divide by 2.2. For example, 10 pounds x 0.45359237 = 4.54 kilograms. The converter above performs the exact calculation as you type, so you do not need to do the math by hand.
One pound of flour weighs 0.45 kilograms (approximately 453.6 grams), regardless of whether it is all-purpose, bread, or cake flour. The weight of a pound is fixed by international standard and does not depend on what is being weighed. A two-pound bag of flour is 0.91 kilograms.
Cookbooks published in the United States and older British cookbooks use pounds because pounds were the standard household weight unit at the time of publication. Many family recipes have been passed down using pound measurements. When following such a recipe in a metric country, converting to kilograms or grams makes shopping and measuring easier with metric kitchen scales.
Not exactly. The international avoirdupois pound is defined as precisely 0.45359237 kilograms by the 1959 international yard and pound agreement. The figure 0.45 kg is a rounded approximation used for quick mental math, accurate to within about 0.8 percent. For formal documents, scientific work, or shipping calculations, use the full precision value.
One kilogram equals 2.20462 pounds. So a 5 kilogram package weighs 11.02 pounds, and a 10 kilogram bag of rice weighs 22.05 pounds. To go from kilograms back to pounds, multiply the kilogram value by 2.20462.
On US customs forms and shipping declarations, "pounds" refers to the avoirdupois pound, the standard commercial weight unit. International shipping carriers convert this to kilograms for processing in metric countries. When filling out a customs form, write the weight clearly with the unit (for example, "12 pounds" or "5.4 kg") to avoid mix-ups during transit.
In the United States, patient weight is typically recorded in pounds on medical charts, with kilogram equivalents noted for medication dosing. Most prescription medications are dosed by kilograms of body weight, so a clinician records both values. An adult patient weighing 154 pounds is 70 kg, which is often used as a reference for adult medication calculations.
No. The British pound (or pound sterling) is a unit of currency, written with the symbol GBP. The pound used for weight is a measurement unit, written as "lb" or "lbs". They share a name because the currency was historically based on a pound weight of silver, but today they are completely separate. Always check the context to know which "pound" is being discussed.
Most national postal services and international carriers set a maximum parcel weight between 50 and 70 pounds (22.7 to 31.8 kilograms) for standard service. The Universal Postal Union limit is generally 30 kg (66.1 pounds) for international parcels, though specific destinations may have lower limits. Always verify with the carrier before sending heavy packages.
The abbreviation "lb" comes from the Latin word "libra", which referred to a Roman unit of weight called "libra pondo" (a pound by weight). Over time, the word "pondo" gave English the word "pound", but the abbreviation kept the original Latin root. That is why "lb" looks nothing like the English word it stands for.
For everyday tasks such as cooking, casual shipping, or fitness tracking, two decimal places of a kilogram is plenty. For medical dosing, lab work, and customs declarations, follow the precision required by the form or protocol. The converter on this page shows results to several decimal places, so you can round as needed for your specific use case.
Yes. "Lbs" and "lb" are just abbreviations of "pounds", so an lbs to kg conversion uses the identical factor of 0.45359237. Whatever label a scale, form, or recipe uses, you enter the same number and get the same kilogram result.
150 pounds equals 68.04 kg. The calculation is 150 multiplied by 0.45359237. This is a common adult bodyweight figure and is often used as a reference in fitness and medical contexts.
140 pounds equals 63.50 kg. To get this, multiply 140 by 0.45359237. For a quick estimate you can divide 140 by 2.2, which gives roughly 63.6 kg.
160 pounds equals 72.57 kg. The math is 160 multiplied by 0.45359237. This sits in the typical adult bodyweight range used for BMI and fitness tracking.
First convert the whole weight to pounds by multiplying the stones by 14 and adding the leftover pounds, since one stone equals 14 pounds. Then multiply the total by 0.45359237. For example, 11 stone 4 pounds is 158 pounds, which equals about 71.67 kg.
Divide the kilogram value by 0.45359237, or multiply it by 2.20462. For example, 70 kg equals about 154.3 pounds. The swap control on the converter above flips between pounds to kg and kg to pounds instantly.