One long ton is exactly 1,016.0469088 kilograms. It is the traditional British ton of 2,240 pounds, and it is the only one of the three tons that is heavier than the metric tonne — by about 1.6 per cent.
About the units
The long ton is 2,240 avoirdupois pounds, which comes from twenty British hundredweight of 112 pounds each. The 112 in turn comes from eight stone of fourteen pounds, so the whole structure builds up from the same fourteen that makes British body weight awkward. It was the standard ton in the United Kingdom and across the Commonwealth for shipping, mining and steel until metrication, and it survives in shipping displacement figures and in some commodity contracts. Its near-equality with the metric tonne is genuinely dangerous: a difference of 1.6 per cent is small enough to look like rounding and large enough to matter across a cargo.
The exact factor
The exact chain is 2,240 × 0.45359237 kg = 1,016.0469088 kg, which is 1.0160469088 tonnes. A long ton is exactly 1.12 short tons, since 2,240 ÷ 2,000 = 1.12, and that relationship is exact in both directions. The three tons in ascending order are: short ton 907.18 kg, tonne 1,000 kg, long ton 1,016.05 kg. Spanning the range from smallest to largest is a difference of twelve per cent.
Where you meet this conversion
Ship displacement and cargo capacity are the main survivals, and maritime sources still use the term long ton or the abbreviation LT. Older British engineering documents, steel specifications and mining records use it throughout, so anyone working with historical industrial data meets it constantly. Some commodity markets retain it by convention. It is worth flagging that the deadweight tonnage of a ship is usually given in metric tonnes today, while older figures for the same vessel may be in long tons, and comparing the two directly overstates any apparent change in capacity.