When something is a litre or more it is probably better to use litres (maybe if something is 1/10 and above of a litre). It's just that when you talk about something about 1ml or so, it can be confusing to mention it as 0.001 litres. say if you have a nanolitre and you state it in litres, it becomes 0.000000001 litres (you have to look at it for a long time to figure out that it's a nanolitre).
Getting to 1000 litres, it's possibly better to start saying 1m3 (assuming the people reading it have the understanding that a metre cubed is 1000 litres)
milliliters
You would typically use liters or gallons to measure the volume of a hot tub.
Liters would be easiest to use.
Liters (Most European and Asian countries quote capacity of refrigerator in liters)
532 liters
Liters!
They would use litres.
You would need to fill about 4.226 US gallon jugs to equal 16 liters.
You would use the number 3.785. Example, gallons x 3.785 = liters
Kiloliters, liters are too small. Trust Points Please!
liters
Liters!! SCIENCE WOOHOO