What is pound?
A pound is a unit of mass in imperial and US customary systems equal to 16 ounces. It is widely used in the United States for body weight, grocery shopping, and general weight measurement.
Real-world uses
Pounds are the primary unit of weight in everyday American life—used for body weight, grocery items, luggage limits, and newborn birth weights. In the UK, pounds remain common for body weight despite official metrication.
History
The pound descends from the Roman "libra pondo" (a pound by weight), which is why its abbreviation is "lb." The avoirdupois pound was standardized internationally in 1959 as exactly 0.45359237 kilograms.
Common mistakes
Confusing pounds-mass (lb) with pounds-force (lbf), which are technically different quantities. Also, assuming the pound symbol "£" relates to weight—it actually denotes British currency, though both derive from "libra."
What is short ton (US)?
A short ton is a unit of mass used primarily in the United States, equal to 2,000 pounds. It is used in industries such as mining, agriculture, and freight transportation.
Real-world uses
The short ton is the standard ton in US commerce and industry, used for coal, grain, and bulk commodity trading. HVAC cooling capacity was traditionally rated in tons (1 ton of refrigeration ≈ cooling of 1 short ton of ice per day).
History
The short ton of 2,000 pounds became standard in the United States as a simplified version of the older English long ton. It gained legal definition in US commerce during the 19th century and remains the default "ton" in American industry.
Common mistakes
Assuming "ton" means the same thing globally. In the US it means 2,000 lb (short ton), in the UK it traditionally meant 2,240 lb (long ton), and internationally it usually means 1,000 kg (metric tonne).
When is this conversion used?
Body weight, grocery items, and luggage limits are commonly expressed in kilograms in most countries and pounds in the US and UK, making this one of the most frequently needed mass conversions.
Worked examples
1 pound = 0.0005 short ton (US)
1 short ton (US) = 907.18474 kilogram
How to convert pound to short ton (US)
To convert pound to short ton (US), multiply the value by 0.0005.
To convert short ton (US) back to pound, multiply by 2,000.
Measurement standards
The kilogram is defined by fixing the Planck constant to exactly 6.62607015 × 10⁻³⁴ joule-seconds, as established at the 26th General Conference on Weights and Measures in 2018. This ended the last SI definition based on a physical artefact.
Did you know?
The International Prototype of the Kilogram, a platinum-iridium cylinder stored near Paris since 1889, was found to have drifted by about 50 micrograms relative to its copies over a century — roughly the mass of a fingerprint.
Quick reference: pound to short ton (US)
| pound | short ton (US) |
|---|---|
| 0.1 | 0.00005 |
| 0.5 | 0.00025 |
| 1 | 0.0005 |
| 2 | 0.001 |
| 5 | 0.0025 |
| 10 | 0.005 |
| 25 | 0.0125 |
| 50 | 0.025 |
| 100 | 0.05 |
| 250 | 0.125 |
| 500 | 0.25 |
| 1,000 | 0.5 |
Common values
| pound | short ton (US) | |
|---|---|---|
| A paperclip | 2.20462262 pound | 0.00110231 short ton (US) |
| A smartphone | 385.80895882 pound | 0.19290448 short ton (US) |
| A bag of sugar | 2.20462262 pound | 0.00110231 short ton (US) |
| Average adult human | 154.32358353 pound | 0.07716179 short ton (US) |
| A small car | 2,645.54714622 pound | 1.32277357 short ton (US) |