Pounds to Tons
Convert pounds (lb) to tons (t). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.
The Formula
``
tons = pounds × 0.00045359237
pounds = tons × 2204.62262185
`
One pound is 4.5359e-4 tons, and one ton is 2,204.62 pounds.
Conversion Table
| Pounds | Tons |
|---|---|
| 1 lb | 4.5359e-4 t |
| 2 lb | 9.0718e-4 t |
| 5 lb | 0.002268 t |
| 10 lb | 0.004536 t |
| 25 lb | 0.01134 t |
| 50 lb | 0.02268 t |
| 100 lb | 0.045359 t |
| 500 lb | 0.226796 t |
| 1,000 lb | 0.453592 t |
The Other Direction
| Tons | Pounds |
|---|---|
| 1 t | 2,204.62 lb |
| 2 t | 4,409.25 lb |
| 5 t | 11,023.11 lb |
| 10 t | 22,046.23 lb |
| 25 t | 55,115.57 lb |
| 50 t | 110,231.13 lb |
| 100 t | 220,462.26 lb |
| 500 t | 1,102,311.31 lb |
| 1,000 t | 2,204,622.62 lb |
What Each Unit Is
Pounds (lb) — exactly 0.45359237 kilograms, by the 1959 international agreement. The Roman libra — which is why its symbol is lb — refined through the English avoirdupois system.
Tons (t) — here the metric tonne: exactly 1,000 kilograms. From the tun, a large wine cask, whose weight became a trade standard.
A Sense of Scale
A bag of sugar is 2 lb- A newborn is 6–9 lb
- US body weight is given in pounds
- A small car is about 1.5 t
- A cubic metre of water is 1 t
- Shipping freight is priced per tonne
Precision
The factor 0.00045359237 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.
Watch Out For
- Three different tons exist: metric (1,000 kg), US short (907 kg) and UK long (1,016 kg). This converter uses the metric tonne.
In Code
`javascript
const poundToTon = (value) => value * 0.00045359237;
``
Where This Conversion Comes Up
- Cooking
- Shipping
- Fitness
- Medicine
- Manufacturing
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 lb with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 lb becomes | Error |
|---|---|---|---|
| 0 | 0 | 0 | 100.0000% |
| 1 | 0 | 0 | 100.0000% |
| 2 | 0 | 0 | 100.0000% |
| 3 | 0 | 0 | 100.0000% |
| 4 | 0.0005 | 0.0685 | 10.2311% |
The right number of significant figures is set by your input, not by the converter. If you measured pounds to three significant figures, the answer in tons is only good to three — writing more digits claims precision the measurement never had.