Common job sizes
A calculator makes you do the measuring first. These pages start with the answer for the size you are actually building, then let you adjust it.
Common deck sizes
Board counts for the deck sizes people actually build.
Common slab sizes
Bag counts, and the point where ready-mix gets cheaper.
Common patio sizes
Paver counts by paver size, plus base and sand.
Building something a different size? Every calculator takes any dimensions you like.