Ramp up to coop clearance height?

[thomp119]

I am building a coop and think I made the floor opening too small. When the ramp is at an acceptable/doable angle for the chickens to climb up from the run to the coop, the clearance is only 7 inches. What type of clearance do bantam silkies need?

If 7 inches is not enough, what would be an acceptable clearance so I can make the cut?

 

[Hokum Coco]

The dimension on my pop door is 9x12 inches and my Delaware rooster has no problem with it. I would say you need another 5 inches of clearance any way.