There are three main measurements you are likely to see given for a dry wall rasp, which are its length, width and height.
Length
This can range from around 140mm (5½”) to 190mm (7½”) depending on the type of rasp. Grate type dry wall rasps are the longest while pocket rasps are the shortest, although the blade length of some rasps such as the shaver type may be considerably shorter.
Width
The width of a dry wall rasp ranges from around 40mm (1⅝”) to 90mm (3½”) depending on the type of rasp, with three-file combination rasps being the widest.
Height
The height can vary from around 25mm (1″) to 50mm (2″) depending on the type of rasp, pocket rasps being the highest and three-file combination rasps being the shortest.
Other dry wall suitable rasp sizes
Two-handled rasp
The overall length of these rasps is much longer than that of other rasps used to shape plasterboard. The flat file type rasp can be up to 440mm (17⅜”) in total length. While the blade length is also much longer than on dry wall specific rasps, it does not extend the entire length of the tool.
Shaver rasp
The shaver rasp has a smaller blade than other rasps and a long handle. The total length is about the same as the longer dry wall specific rasps but the blade length is roughly about half the size.
Multi-tool rasp
It’s difficult to give an exact size for multi-tool rasps as they can have unusual shapes or sections that fold out. They are, however, designed to fit in most trouser and tool belt pockets.