Pounds to kg Conversion: Formula & Chart

One pound equals 0.453592 kilograms, so to convert pounds to kilograms, multiply the number of pounds by 0.453592. That single multiplication handles everything from a body-weight check to an airline luggage limit. Whether you are reading a European recipe, filling out a medical form abroad, or comparing gym weights, the pounds-to-kilograms conversion is the one travelers, cooks, and athletes use most.

The pound is an imperial unit with roots in the Roman libra, and the avoirdupois pound used today was fixed at exactly 0.45359237 kilograms by international agreement in 1959. The kilogram is the metric base unit of mass, defined by a physical constant since 2019 and used by nearly every country in the world. Because the United States still weighs people, food, and luggage in pounds while most of the world uses kilograms, knowing how to move between the two keeps you fluent anywhere. This guide gives you the exact formula, worked examples, a fast mental trick, and charts of the weights people look up most.

Pounds to Kilograms Conversion Chart

Start with the quick reference table. Find your pounds in the left column and read the kilogram value on the right.

Pounds	Kilograms
50 lb	22.68 kg
100 lb	45.36 kg
120 lb	54.43 kg
150 lb	68.04 kg
180 lb	81.65 kg
200 lb	90.72 kg
250 lb	113.40 kg
300 lb	136.08 kg

Values are rounded to two decimal places, which is more than enough precision for luggage, fitness, and everyday weighing.

Everyday Reference Weights

These familiar objects help you feel what a pound or a kilogram really is.

Reference	Pounds	Kilograms
Airline checked-bag limit (typical US)	50 lb	22.68 kg
Gallon of water	8.34 lb	3.79 kg
Average newborn baby (rough)	7.5 lb	3.40 kg
Typical adult bowling ball	14 lb	6.35 kg
Standard clay brick (rough)	4.5 lb	2.04 kg
Smartphone (rough)	0.4 lb	0.18 kg
Medium dumbbell	20 lb	9.07 kg

Rough figures vary by brand and model, so treat the brick and smartphone rows as ballpark estimates.

1. The Formula: Pounds to Kilograms

The exact conversion formula is simple: kilograms = pounds × 0.453592. Because the international avoirdupois pound is defined as exactly 0.45359237 kilograms, multiplying by 0.453592 captures the definition to six decimal places. The formula works at every scale, from a few ounces of flour to hundreds of pounds of freight, and it never changes. Keep 0.453592 saved in your phone notes and you will always have the conversion ready. For the reverse trip, kilograms to pounds, multiply by 2.20462 instead.

2. Worked Example: 1 Pound to Kilograms

Take the base case first: 1 pound × 0.453592 = 0.453592 kilograms, usually rounded to 0.454 kg or simply “just under half a kilo.” This is the number behind the familiar fact that a pound is a little less than half a kilogram. If a recipe calls for a pound of flour and your scale reads metric, aim for about 454 grams. Rounding to 0.45 kg introduces an error of less than a teaspoon of flour, which is negligible in cooking. For most kitchen and household purposes, remembering that a pound is roughly 450 grams is all you need.

3. Worked Example: Converting Larger Weights

Scale the formula up the same way. One hundred pounds: 100 × 0.453592 = 45.3592 kg, about 45.4 kg. Two hundred pounds: 200 × 0.453592 = 90.7184 kg, about 90.7 kg. The decimal point simply shifts as the pounds grow, so converting 150 pounds (68.0388 kg) feels no harder than converting 15 pounds (6.8039 kg). Freight shippers use this when a US customer quotes pounds and the carrier’s system expects kilograms. A 500-pound pallet, for instance, becomes 226.8 kg on the shipping paperwork.

4. The Divide-by-2.2 Mental Trick

When you need an answer in your head, divide the pounds by 2.2 instead of multiplying by 0.453592. For 150 pounds: 150 ÷ 2.2 = 68.18 kg, very close to the exact 68.04 kg. For 200 pounds: 200 ÷ 2.2 = 90.91 kg, versus the exact 90.72 kg. The error stays well under half a percent, which is fine for conversation, fitness tracking, and travel. An even rougher version — halve the pounds and subtract a tenth of the result — works too: half of 150 is 75, minus 7.5 gives 67.5 kg. Save the full 0.453592 for luggage limits, medical doses, and shipping labels.

5. Common Body Weights: 100 to 200 Pounds

These are the weights people convert most often, usually their own. One hundred pounds is 45.36 kg. One hundred twenty pounds is 54.43 kg. One hundred fifty pounds is 68.04 kg. One hundred eighty pounds is 81.65 kg. Two hundred pounds is 90.72 kg. Doctor’s offices, gym sign-up forms, and travel insurance questionnaires in metric countries all ask for kilograms, and answering from memory beats fumbling with a phone calculator. Many people memorize just their own number — for example, “I am 68 kilos” for 150 pounds — and that single anchor makes the whole system feel familiar.

6. Luggage Limits: 50 Pounds Is 22.7 kg

Airline baggage rules are the classic real-world conversion. The standard US checked-bag limit of 50 pounds equals 22.68 kg, usually rounded to 23 kg on international airline sites. Go over and you pay overweight fees, which is why travelers weigh bags at home. Carry-on limits vary by airline but often sit around 15 to 22 pounds (7 to 10 kg), so check your carrier’s rule before you pack. A handheld luggage scale that toggles between units removes all doubt. When in doubt, pack to 22.5 kg and you will clear the 50-pound limit with margin to spare.

7. Gym Weights: Plates, Dumbbells, and Bars

Gyms mix both systems, which makes this conversion a workout staple. A standard 45-pound Olympic plate is 20.41 kg, close to the 20 kg plates used in metric gyms. A 25-pound plate is 11.34 kg, and a 10-pound plate is 4.54 kg. Dumbbells follow the same math: 20-pound dumbbells are 9.07 kg each. The classic 45-pound Olympic barbell is 20.41 kg, while a true metric Olympic bar is 20 kg flat — close enough that lifters treat them as interchangeable. If your program is written in kilos and your gym’s plates are in pounds, convert your working sets once and write both numbers in your training log.

8. Cooking Weights: Pounds, Ounces, and Grams

American recipes weigh ingredients in pounds and ounces while much of the world uses grams. One pound is 453.6 grams, half a pound is 226.8 grams, and a quarter pound is 113.4 grams — the weight of a standard stick of butter, which is also 4 ounces. A 5-pound bag of flour is 2.27 kg, and a 2-pound bag of sugar is 907 grams. Kitchen scales that switch units with one button press are the easiest fix, but the conversion matters when scaling recipes: doubling a recipe that calls for 1.5 pounds of meat means weighing out about 1.36 kg. For baking, where precision matters most, convert with the full factor rather than the mental shortcut.

9. Baby and Child Weights

Pediatric charts in metric countries track growth in kilograms, so parents convert often. An average newborn weighs around 7.5 pounds, about 3.4 kg. By six months, many babies weigh roughly 16 to 18 pounds (7.3 to 8.2 kg), and by their first birthday roughly 21 to 23 pounds (9.5 to 10.4 kg) — wide ranges, since healthy babies vary a lot. Car seats add another conversion: an infant seat rated to 35 pounds holds a child up to 15.9 kg, and a convertible seat rated to 65 pounds covers up to 29.5 kg. When traveling with little ones, knowing both numbers keeps you inside every safety rating.

10. The Reverse: Kilograms to Pounds

To go the other way, multiply kilograms by 2.20462. So 70 kg × 2.20462 = 154.32 pounds, about 154 lb. A 10 kg dumbbell is 22.05 pounds, and a 25 kg checked bag is 55.12 pounds — over the typical 50-pound limit, so repack. The mental shortcut works in reverse too: double the kilograms and add ten percent. For 70 kg, double to 140 and add 14 to get 154 pounds, remarkably close to the exact 154.3. Europeans moving to the US use this to translate their known weight: “I was 80 kilos” becomes “about 176 pounds.”

11. Shipping and Freight Conversions

Carriers price freight by weight, and the unit on the quote depends on the country. A 100-pound parcel is 45.36 kg; a 1,000-pound pallet is 453.59 kg. US Postal Service international forms ask for kilograms, so a 3-pound package ships as 1.36 kg. Dimensional-weight pricing adds a twist — carriers charge by volume when a box is light but bulky — but the scale weight underneath still converts the same way. When moving house, heavy furniture needs both a weight check and a fit check: a 200-pound sofa converts to 90.7 kg on paper, but it still has to pass through the doorway, so confirm the standard door size before moving day. Small businesses shipping abroad convert every product weight once, store both numbers in their catalog, and never think about it again.

12. Medical and Health Contexts

Medicine is one place where exact conversion matters. Drug doses are often calculated per kilogram of body weight, so a 150-pound patient is entered as 68.04 kg — using the rounded 68 kg is standard practice, but the precise figure is the starting point. Hospital scales in the US read pounds; the chart gets kilograms. Fitness assessments use both: body mass index needs kilograms and meters, so a 180-pound person first converts to 81.65 kg. Because health decisions rest on these numbers, this is one context where the full 0.453592 factor beats the divide-by-2.2 shortcut.

13. Weighing Produce and Groceries Abroad

Grocery shopping in a metric country means converting on the fly. A pound of apples is 454 grams — look for the 500-gram bag and you are close. Two pounds of potatoes is 907 grams, just under a kilo. Deli counters sell by the 100-gram unit, so a “pound of turkey” becomes roughly 450 grams. Market vendors round cheerfully, and being within a few percent is fine for dinner. The conversion also helps you compare prices: if chicken is $4 per pound at home and €8 per kilo abroad, convert first — €8 per kilo is about $3.95 per pound at typical exchange rates, so the prices are closer than they look.

14. Why the US Still Uses Pounds

The United States is one of only a few countries that has not fully adopted metric weights in daily life, alongside Liberia and Myanmar. A 1970s metrication push stalled, and the cost of replacing every scale, sign, and label in the country kept pounds in place. Science, medicine, and the military went metric anyway, which is why American life runs on both systems at once. The UK uses a hybrid — stones and pounds for body weight, metric for most else. This split is exactly why the pounds-to-kilograms conversion stays essential: it bridges the two systems every time an American cooks, travels, or trains internationally.

15. Rounding Rules: When Precision Matters

Round to the situation. For conversation and fitness tracking, whole kilograms are plenty: 150 pounds is 68 kg. For luggage, keep one decimal: 22.7 kg tells you whether you clear the limit. For medicine, shipping, and engineering, use the full factor and keep two or more decimals: 68.04 kg. Never round before the final step of a multi-part calculation, since early rounding compounds the error. And remember that converting a rounded number cannot recover lost precision — “about 68 kg” from a rounded 150 pounds is honest, while “68.0388 kg” from the same input only pretends to be exact.

Frequently Asked Questions

How many kg is 150 pounds?

150 pounds equals 68.04 kilograms (150 × 0.453592 = 68.0388 kg). This is one of the most converted body weights, since 150 lb sits near the average adult weight in the US. For everyday purposes, saying 68 kg is perfectly fine.

What is the quick way to convert pounds to kg in your head?

Divide the pounds by 2.2. For example, 180 ÷ 2.2 = 81.8 kg, versus the exact 81.65 kg — close enough for conversation, travel, and fitness tracking. For luggage limits, medical doses, and shipping, use the exact factor of 0.453592 instead.

How many pounds is 70 kg?

70 kilograms equals 154.32 pounds (70 × 2.20462). The reverse shortcut also works: double the kilograms and add ten percent — double 70 is 140, plus 14 gives 154 pounds, very close to exact.

Is a kilogram heavier than a pound?

Yes. One kilogram equals 2.20462 pounds, so a kilogram is a little more than twice as heavy as a pound. Conversely, a pound is just under half a kilogram (0.453592 kg). When you track fitness goals, pair your scale with body measurements — our guide on how to read a measuring tape shows how to take waist and chest measurements accurately alongside your weight.

Final Thoughts

Converting pounds to kilograms comes down to one number, 0.453592, and one habit: multiply pounds by it, or divide by 2.2 when an estimate will do. The chart above handles the weights people look up most, from a 50-pound suitcase to a 300-pound freight pallet, while the reverse factor 2.20462 translates kilograms back just as easily. Cooks get daily use from it when a recipe crosses the Atlantic, travelers need it at every baggage scale, and lifters live by it whenever plates and programs use different units. Keep the formula, the divide-by-2.2 shortcut, and the reverse multiplier within reach, and the two systems stop feeling like two languages. Weight is weight — the units are just the accent. Once the conversion becomes automatic, reading foreign labels and filling out international forms feels completely natural.