In the SI system the derived unit is the cubic metre. Divisions of this are litres and millilitres etc.
Other systems use other units. They include any cubic measurement and such specialised units such as gallons, pints, cups, etc.
You can cube any unit of length: cubic meter, cubic millimeter, cubic decimeter , cubic light-year, cubic inch, cubic foot. There are also non-standard (non-SI) units for volume that are not directly derived from a length, for example in the imperial system, the gallon, the bushel, etc. One weird thing about these units is that different units are used to measure liquids than to measure grains, for example.
Also, apparently identical units (the gallon, for example) are different on either side of the Atlantic!
See the link below for around 100 units of volume. There are many more!
That depends entirely on the system you're asking about. I'll just compare the primary English units to the SI units.
English:
Fl oz (fluid ounce)
Cup (8 fl oz)
Pint (2 cups, 16 fl oz)
Quart (2 pints, 4 cups, 32 fl oz)
Pottle, or half gallon (2 quarts, 4 pints, 8 cups, 64 fl oz)
Gallon (2 pottles, 4 quarts, 8 pints, 16 cups, 128 fl oz)
There are some other units of measurement within the English system, but they are almost never used in everyday life.
Pints
The volume of a bucket can vary, but a standard bucket typically holds around 10 liters of water. It's important to note that the exact volume can depend on the size and shape of the bucket. To determine the precise volume of water in a specific bucket, you can fill it with water and then measure the volume using a measuring cup or container with liter markings.
mL, L, cm3, m3 are all SI units that can be used to measure the volume of water.
To calculate the volume of an irregularly shaped object, a good idea would be to get a bucket full of water and submerge that object into the bucket. Then measure the amount of water that runs over and that should be the volume of your object. For example if you take a sealed bottle of bottle stick it in a bucket filled with water, then let it's volume filll the space and displace the water. The water that is displaced or the water that runs out is the volume of your irregular shape. Get it?
It depends on the volume of the bucket.
a bucket...
The standard unit of volume in the metric system is liter or litre. By using decimal prefixes we can arrive at smaller or larger units of measure. It is no coincidence that there is a relationship between liter as volume, meter as distance and water:1 liter = 1 cubic decimeter = 1 kilogram of water at 4° C.
You can measure the volume of liquid water using a graduated cylinder, measuring cup, or a beaker. Simply pour the water into the container and read the volume marking at the meniscus level for an accurate measurement.
milliliter
You could.
1 US gallon = 3.78541178 liters. Only if you mean pure water, then 1000 litres of water weighs 1 metric tonne. 1000 litres of water are 264.172052357 gallons that weigh 1 metric tonne.
One metric ton of plain water has a volume of about 35.32 cubic feet.