Is my speed to my Hub acceptable at 18.7 mb/s?

[Otterman]

I've got Sky Broadband Superfast and multiple devices connected - 4 people in the house, 2 teenage boys. WiFi keeps dropping. Speed to Hub is 18.7 mb/s. When I checked WiFi download speed it's 12 mb/s. One boy has his PC connected through TP-Link, but 2nd TP-Link doesn't work for other boy as I think house extension wire is on sperate circuit, so he uses WiFi. Is speed to Hub good? What can be done better so WiFi doesn't drop?

[TimmyBGood]

@Otterman 

Putting the address into the BT Wholesale Availability Checker should indicate the Openreach estimate of FTTC speed available at your address: this is almost entirely a factor of copper line distance from the fibre cabinet.

https://www.broadbandchecker.btwholesale.com/#/ADSL/AddressHome 

It's the table and the two text lines below it which are most useful.

Remove any personal information (such as the address itself) if you post an image.