I like it! Seems fair to both parties.

By following a simple formula

Start when they move in. Let them know the carpet is expected to last "x" number of years of use. The difference between is what they could be charged for n

Check the law in your state

At my previous company, we went off of pictures from the turn before they moved in. If someone had lived in the apartment for 5 years and they moved out and it was nasty, whatever we replace it. But if we replace the carpet, hand it over and they move out a year later and it’s wrecked, that’s on them. Also if at any point there’s excessive damage from pets that it needs to be replaced, regardless of age. They tend to get replaced every 5-8 years anyway.

Johnny Karnofsky yes they would have been charged 2 years plus any additional damages.