Pound (lb) Weight Conversion Calculator

Pound Conversion Calculator

Enter a value in pounds below to convert to another unit of weight.

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Do you want to convert pounds to ounces, kilograms, or gallons?

What is a Pound?

A pound is a unit used to measure weight.

The pound is a US customary and imperial unit of weight. A pound is sometimes also referred to as a common ounce. Pounds can be abbreviated as lb (plural lbs), and are also sometimes abbreviated as lb_m or #. For example, 1 pound can be written as 1 lb, 1 lb_m, or 1 #, and 2 pounds can be written as 2 lbs.

Background and Origin

The pound originates from the libra, which is where the abbreviation "lb" comes from. The libra was a Roman unit of mass equal to 328.9 grams, or about 123 ounces.^[1]

Over time, the libra was replaced by variations of the pound, such as the tower pound and the troy pound. Eventually it evolved into the modern variation, the avoirdupois pound.

How Much is a Pound?

Pounds are a widely used unit of weight in the United States. The National Bureau of Standards approved the international definition of the pound for use in the United States in 1959 after an agreement between six nations referred to as the International Yard and Pound Agreement.^[2]

One pound is equal to 16 ounces, or 0.45359237 kilograms. In the avoirdupois or apothecaries' systems, one pound is equal to 7,000 grains.^[3]

How to Convert Pounds

To convert pounds to another unit of weight, you need to multiply the value by a conversion factor. A conversion factor is a numerical value used to change the units of a measurement without changing the value.^[4]

You can find the conversion factors for pounds in the conversion table below.

Then, multiply the weight measurement by the conversion factor to find the equivalent value in the desired unit of measurement.

pounds × conversion factor = result

You can also use a calculator, such as one of the converters below, for the conversion.

Pound Conversion Table

Common pound values and equivalent imperial and metric weight measurements
pounds	tons	ounces	metric tons	kilograms	grams	milligrams	calories	stones	long tons	carats
1 lb	0.0005 t	16 oz	0.000454 t	0.453592 kg	453.59237 g	453,592 mg	3,500 kcal	0.071429 st	0.000446 lt	2,268 ct
2 lb	0.001 t	32 oz	0.000907 t	0.907185 kg	907.18474 g	907,185 mg	7,000 kcal	0.142857 st	0.000893 lt	4,536 ct
3 lb	0.0015 t	48 oz	0.001361 t	1.360777 kg	1,361 g	1,360,777 mg	10,500 kcal	0.214286 st	0.001339 lt	6,804 ct
4 lb	0.002 t	64 oz	0.001814 t	1.814369 kg	1,814 g	1,814,369 mg	14,000 kcal	0.285714 st	0.001786 lt	9,072 ct
5 lb	0.0025 t	80 oz	0.002268 t	2.267962 kg	2,268 g	2,267,962 mg	17,500 kcal	0.357143 st	0.002232 lt	11,340 ct
6 lb	0.003 t	96 oz	0.002722 t	2.721554 kg	2,722 g	2,721,554 mg	21,000 kcal	0.428571 st	0.002679 lt	13,608 ct
7 lb	0.0035 t	112 oz	0.003175 t	3.175147 kg	3,175 g	3,175,147 mg	24,500 kcal	0.5 st	0.003125 lt	15,876 ct
8 lb	0.004 t	128 oz	0.003629 t	3.628739 kg	3,629 g	3,628,739 mg	28,000 kcal	0.571429 st	0.003571 lt	18,144 ct
9 lb	0.0045 t	144 oz	0.004082 t	4.082331 kg	4,082 g	4,082,331 mg	31,500 kcal	0.642857 st	0.004018 lt	20,412 ct
10 lb	0.005 t	160 oz	0.004536 t	4.535924 kg	4,536 g	4,535,924 mg	35,000 kcal	0.714286 st	0.004464 lt	22,680 ct
11 lb	0.0055 t	176 oz	0.00499 t	4.989516 kg	4,990 g	4,989,516 mg	38,500 kcal	0.785714 st	0.004911 lt	24,948 ct
12 lb	0.006 t	192 oz	0.005443 t	5.443108 kg	5,443 g	5,443,108 mg	42,000 kcal	0.857143 st	0.005357 lt	27,216 ct
13 lb	0.0065 t	208 oz	0.005897 t	5.896701 kg	5,897 g	5,896,701 mg	45,500 kcal	0.928571 st	0.005804 lt	29,484 ct
14 lb	0.007 t	224 oz	0.00635 t	6.350293 kg	6,350 g	6,350,293 mg	49,000 kcal	1 st	0.00625 lt	31,751 ct
15 lb	0.0075 t	240 oz	0.006804 t	6.803886 kg	6,804 g	6,803,886 mg	52,500 kcal	1.071429 st	0.006696 lt	34,019 ct
16 lb	0.008 t	256 oz	0.007257 t	7.257478 kg	7,257 g	7,257,478 mg	56,000 kcal	1.142857 st	0.007143 lt	36,287 ct
17 lb	0.0085 t	272 oz	0.007711 t	7.71107 kg	7,711 g	7,711,070 mg	59,500 kcal	1.214286 st	0.007589 lt	38,555 ct
18 lb	0.009 t	288 oz	0.008165 t	8.164663 kg	8,165 g	8,164,663 mg	63,000 kcal	1.285714 st	0.008036 lt	40,823 ct
19 lb	0.0095 t	304 oz	0.008618 t	8.618255 kg	8,618 g	8,618,255 mg	66,500 kcal	1.357143 st	0.008482 lt	43,091 ct
20 lb	0.01 t	320 oz	0.009072 t	9.071847 kg	9,072 g	9,071,847 mg	70,000 kcal	1.428571 st	0.008929 lt	45,359 ct

References

Arika Okrent, Why are pound and ounce abbreviated as 'lb' and 'oz'?, The Week, https://theweek.com/articles/461362/why-are-pound-ounce-abbreviated-lb-oz

National Bureau of Standards, Refinement of Values for the Yard and Pound, U.S. Department of Commerce, July 1, 1959, https://www.nist.gov/system/files/documents/2017/05/09/frn-59-5442-1959.pdf

Encyclopædia Britannica, Avoirdupois weight, https://www.britannica.com/science/avoirdupois-weight

National Institute of Standards & Technology, Unit Conversion, https://www.nist.gov/pml/owm/metric-si/unit-conversion