Can a landlord require a larger income requirement for new tenant

[Basit Siddiqi]

Hello everyone,

Can I require a larger income requirement for those that have children than those without children?(without it being considered illegal)

For example can I require 
Singles to make 40X rent and Singles with children 50X rent?

The purpose is not to discriminate those with families/children. 
It cost more to support a family than not having to support a family.

A quick google search did not pull up any results.
I was also not able to see anything on biggerpockets(I may have wrote the wrong words).

I have a feeling this would be considered illegal but I thought i'd ask!

I would greatly appreciate if there is any legal literature/examples.

Thanks in advance!
Basit