Can you help me estimate what I'd expect for retirement as a guardsman?

I’ve never really had a firm grasp on how the retirement pay structure worked for retired guardsmen.

I sometimes wonder what’s keeping me in the guard… and the answers are typically retirement, educational benefits, and seeing friends I wouldn’t ordinarily see.

I suppose what I’m asking is… Upon completing my college degree, would it be worth staying in the guard until retirement? Can you help me figure out how much I’d realistically expect to receive after 20 years of service? For the sake of helping me come up with a figure, let’s assume I retire as an E-7.

Any words of advice or personal experience would be greatly appreciated.

Thanks.