| Teraliters (TL) | Fluid ounces (fl oz) |
|---|---|
| 1 Teraliter | 35195079727854 fl oz |
| 2 Teraliters | 70390159455708 fl oz |
| 3 Teraliters | 105585239183562 fl oz |
| 4 Teraliters | 140780318911416 fl oz |
| 5 Teraliters | 175975398639270 fl oz |
| 10 Teraliters | 351950797278540 fl oz |
| 20 Teraliters | 703901594557081 fl oz |
| 25 Teraliters | 879876993196351 fl oz |
| 50 Teraliters | 1.75975398639 × 1015 fl oz |
| 100 Teraliters | 3.51950797279 × 1015 fl oz |
| Reference | Teraliters (TL) | Fluid ounces (fl oz) |
|---|---|---|
| A teaspoon | 5 × 10-15 TL | 0.175975 fl oz |
| A can of soft drink | 3.3 × 10-13 TL | 11.6144 fl oz |
| A wine bottle | 7.5 × 10-13 TL | 26.3963 fl oz |
| A bathtub | 1.5 × 10-10 TL | 5279.26 fl oz |
| An Olympic swimming pool | 0.0000025 TL | 87987699 fl oz |
The teralitre is a unit of volume equal to a thousand gigalitres, or 1,000,000,000,000 litres. Its symbol is TL. It is exactly one cubic kilometre, and that is how the quantity is almost always written, because at this scale what is being measured is no longer a container but a piece of the planet.
Lakes are the obvious application. Lake Baikal holds about 23,600 cubic kilometres of fresh water, more than any other lake on earth, and Lake Superior about 12,100. Those two figures alone amount to a fifth of the world's unfrozen surface fresh water, which is the kind of statement the unit exists to make.
Rivers are described by the volume they move rather than by what they hold. The Amazon discharges roughly 6600 cubic kilometres a year into the Atlantic, more than the next several rivers combined, and total human withdrawal of fresh water from all sources runs to about 4000 cubic kilometres a year. Setting those two numbers side by side in the same unit is one of the clearest ways to state the scale of water use.
Ice is measured here too, and the numbers are larger again. The Greenland ice sheet contains close to 2.9 million cubic kilometres, and in recent decades it has been losing a few hundred each year, a figure that converts directly into millimetres of sea level because the ocean's surface area is known. The Antarctic sheet is an order of magnitude larger still.
The ocean itself sets the ceiling. All the seawater on earth amounts to about 1.335 billion cubic kilometres, so a single teralitre is roughly one billionth of it. Below the ocean, the largest managed water bodies are engineered reservoirs, and even the biggest of those hold only a few tens of cubic kilometres.
In practice the name teralitre is rare and the cubic kilometre is standard. Hydrology, glaciology and climate science all use km³, and a figure given in teralitres is more likely to come from a water utility extending its own gigalitre scale upward than from a scientific source. The two are identical, so no conversion is needed, only recognition.
One teralitre equals 1,000,000,000,000 litres, 1,000,000,000 cubic metres, 1 cubic kilometre, or 1000 gigalitres.
The fluid ounce in the imperial system is a unit of volume equal to exactly 28.4130625 millilitres. Its symbol is fl oz. Twenty of them make an imperial pint and 160 an imperial gallon. It is the smallest unit of the imperial liquid chain in ordinary use, and its name records exactly what it was built to do.
The name is literal. The Weights and Measures Act of 1824 defined the fluid ounce as the volume occupied by one avoirdupois ounce of water, so a fluid ounce of water weighs an ounce. The modern definition is metric and the agreement is no longer exact, but it is close: a fluid ounce of water weighs 28.4 grams against the ounce's 28.35, a difference of two parts in a thousand.
The United States fluid ounce is a different quantity, and the relationship between the two is the most confusing pair of units in either system. A United States fluid ounce is 29.5735 millilitres, so it is four per cent larger than the imperial one. Yet a United States pint contains only sixteen of them where an imperial pint contains twenty, so the American pint ends up seventeen per cent smaller. The smaller unit belongs to the larger system and the larger unit to the smaller.
That reversal has practical consequences. A recipe calling for eight fluid ounces of milk means 237 millilitres in America and 227 in Britain, which is tolerable, but one calling for a pint means 473 or 568, which is not. Cosmetics, medicines and drinks all carry both figures on internationally sold packaging for exactly this reason.
British labelling now leads with millilitres. Toiletries, spirits and soft drinks are specified in metric units, with fluid ounces printed alongside for markets that expect them, and pharmacy long ago abandoned the fluid ounce and the fluid dram in favour of millilitres. What survives is culinary and conversational rather than legal.
Where an old British recipe uses it, the conversion is straightforward as long as the system is known: multiply by 28.4 for millilitres, and remember that the pint above it holds twenty and not sixteen. Getting the pint right matters more than getting the ounce right, because the error compounds with quantity.
One imperial fluid ounce equals 28.4130625 millilitres, 1/20 of an imperial pint, or about 0.961 US fluid ounces.