Poor wifi speeds

I am getting 27 down when I have the 100 plan. The direct ethernet link is getting 100+. I have tried 3 different WiFi routers and the speeds are the same. Is there anything I can do to get better speeds? I have tested with and without the range extender and the speeds are the same. There are 5 devices connected and as much as 7 only 3 days a week.

Routers: Apple airport extreme, Netgear C3000, Linksys X2000

Modem: Cisco DOCSIS 3, DPC3010