In a regular pushup (with your back horizontal and with no incline) you lift approximately 64% of your bodyweight. 

With a knee pushup you lift approximately 49 percent of your bodyweight. 

And as I said, this changes as the level of hand and foot elevation changes. 

Here are pushup variations by a variety of people (and brands). 

Video credits to Athlean-X. 

Video credits to Simeon Panda.