>>1784671You want the tarp to be as long as your hammock is, ie an 11’ long hammock will fit under an 11’ long tarp. With that setup you’ll have ~11” covering each end of your hammock.
Width is a matter of preference. 9’ wide is seen as a sort of average size (the Warbonnet Mamajamba is pretty popular, and it’s 11x9). Smaller tarps and asym shapes like pic related sacrifice coverage for weight.
