When is it time for new running shoes? A rookie wants to know...

I think I'm ready for a new pair of sneakers, but I'd like to squeeze a couple more months out of them if at all possible since I've got school bills and other shenanigans going on right now. That got me wondering --- how do you know when you really need new ones? I've heard some people make that decision based on mileage (which I have NOT been keeping track of at all...) and others say every 6 months. Is it like getting an oil change for your car; do it whichever comes first, the mileage or the time?

I don't think I'm anywhere near the mileage marker (I think I heard someone once say 500), but my shoes are almost 1 year old. They still look good, and I plan to keep them for things like mowing the lawn and just hanging around. They still feel good when I run, but the last thing I want to do is get injured, sooooo....

What's your rule of thumb on shoes? Let's hear them!

I'm not good about keeping track of the mileage either, but my feet and legs tell me when it's time.  I'm probably around the 300-mile mark when I need new ones as I'm a little over 150#.  I buy about 3 pair a year.  My mileage also varies depending on what I'm training for, so when training for a marathon I'll need them sooner than when I'm not.

I know they're expensive, but lots cheaper than an injury... 

Linn

I just read an article on active.com about this.
They said 300-500 miles, but that will vary based on your weight and how you run.
You can also look at the side of the rubber sole.  If you start to see wear there I call them wrinkles then the sole is breaking down and it's time to replace them.  Generally the side of the sole is nice and smoothe except for what is there for looks, it's when you start seeing changes to the structure that weren't there as part of the original design.

Scott

I got mine before the Disney Marathon in January and I wont get new ones till a few weeks before my half in October.  Usually, I am a 6 month guy because I weigh about 255 but I am not in the possition now to get new ones so I will beat the hell out of these.

I only wear them when jogging - that will extend their life.  I replace them twice a year, regardless of any other issues however, if I start to feel some shin pain I wear them to Lady Footlocker, try on a new pair and walk around the store for a few seconds and I instantly know that it's "time"... For me, it's usually three pairs a year.  I buy mid-grade New Balance.  I've gone with the top models before but really didn't notice any difference in wear or comfort.

I am not very good about keeping track of my mileage, but my feet, back and hips will tell me when it is time to get new shoes.  I am usually good for about 3 - 4 months, depending on how much I am running. (I think I average about 20 - 25 miles per week).   I am a bit on the heavy side (167 lbs) so I tend to wear through my shoes a little faster. 

Thanks for all the input everyone. I think it's time to start investigating a new set.