Sansar uses real life sizes. Make sure you set your 3D software to the dimensions that you prefer. You may create in either Metric or Imperial dimensions. In either case, the size will not change when you import it into Sansar.
The dimensions (measurements) of your model are not shown in the edit window in Sansar. You can scale your object in Sansar with a slider or a numeric factor. The scaling of the object is always in relation to the size it was when it was imported into Sansar. You will not be able to read the actual dimensions of your object in the edit window. The scale ranges from 0.1x to 10.0x. This will give you an idea of the size that your model should be when it is created and exported from your 3D software.
4km x 4km x 4km (4096m) square
Male avatar is 0.8m wide, 1.71m (~5'8") tall
Steps / Stairs
Maximum rise (height of one riser) 0.20m or 20cm
This height is based on tests of both male and female avatars by Ethos Erlanger using a single step.