Molecular Weight to Size Calculator

How big is a protein molecule?

Protein M 5 kDa 10 kDa 20 kDa 50 kDa 100 kDa 200 kDa 500 kDa
Rmin (minimum radius) 1.1 nm 1.42 nm 1.78 nm 2.4 nm 3.05 nm 3.84 nm 5.21 nm

For more information, see Erickson, Biological Procedure Online vol. 11, no. 1.