My net speed is 36mbps when plugged in but when I go wireless it maxes out at 13mbps, I have an actiontec N router, any way I can fix this?

Units! You mean 36 Mbps (Megabits/second) not 36 mbps (millibits/second). The former is 1 billion times faster (10^9) than the latter.

Your router is not the only thing affecting your wireless speed. What speed adapter have you got in your device? Are other devices connected to the same wireless network? Are there other networks in the area that might be conflicting with your network. Has the device (computer) got enough processing power? How many metres between the router and the device (speed drops off as distance increases)?

Wireless networks will only give you about 50% of the speed of the slowest device currently connected to the network. You might be close to the router, but a slow device many feet further away can drag the speed down. Wireless drivers often take more CPU power than Ethernet drivers and a slow CPU can bring the wireless speed down.

I hope this helps.

Not really much you can do besides maybe upgrading your router or computer. Wireless has different modes which operate at different "theoretical" speeds. You say your router operates using the "N" technology, but if your computer isn't compatible with "N" technology then they will negotiate a different mode that both support and use that.

Wireless N has a theoretical maximum speed of 300Mb/s, but you can will never be able to run at the theoretical maximum speed.

I bet what has happened is your computer doesn't support the N technology and it has negotiated a lower speed connection with your router. Most likely the "G" technology which runs at a maximum of 54Mb/s. The majority of this speed being lost in things like overhead, interference, etc.

Wifi is sporadic and many things can affect the signal. Your environment is just as important as the router you choose, but it is usually hard to gauge just how your environment will affect the signal.

Automatically 1/2 the bandwidth of a wired connection, that's the bandwidth you can expect when you go wifi.