It's pretty simple to decide what the standard is: a tile is the cube circumscribed around a dwarf. Presumably then long humanoids can walk in 1-square tunnels crouched (with all the disadvantages that implies). Dwarves, kobolds, short goblins can run freely. Which makes sense, they're the underground dwellers after all: they would be 1 square. I tend to see the long humanoids as two squares in height in that scheme. So a square would be appr. 1 m³. That's 150 liters per level, and that means 15 buckets. Workable.
Please actually read the
Volume and Mass thread and post there if you are talking about that thread...
Again, standard story height, for a human building to be two-story, and have each story be exactly one z-level above the other, would require a 10-foot vertical spacing between z-levels. Dwarves might require slightly shorter (being 6/7ths the volume and mass of humans), but we can assume similar scales, especially if you have to buttress a stone floor.
10 feet also almost perfectly matches 3 meters. 3 meters cube makes for 27 cubic meters, or 27,000 liters of volume.
1 cubic meter is simply far too small for a dwarf. Yes, they are "dwarves", but they aren't LESS THAN HALF the height of a human, especially since a human is comfortable in a 1-z tall house with another floor 1-z level above him.
Dwarves are defined in the raws as, on average, 60,000 ml of volume (and humans 70,000 ml). All organic tissue appears to have a density of 1 kg/l or 1000 kg/m
3 (and kg/m
3 perfectly matches the standard Toady has set for density in the raws, and all references to SIZE imply consistantly that it is measured in ml, density in kg/m
3, and mass in kg.
Wagons are defined as having a volume of a laughably small 12 liters (although, presumably, as a container, may take up more area than that implies). Whales are defined as 20,000 liters.