There are some reasons behind why your Wifi is so slow:
Router positioning
Leaving your router on the ground or behind other objects usually results in noticeably worse performance. Try putting the router as high up as possible to extend the broadcasting range of the radio wave and avoiding placing your router in your basement.
Wireless Interference & Noise
The amount of radio noise, LED lights, bluetooth devices can still cause interference.
Check your speed
You may run a speed test on speedtest.net or 192.168.0.1.
Try resetting your router
Turn Off Bandwidth-Hogging Plugins and Apps