How accurate is the dashboard air filter counter

[70 Mach 1]

My 24 XT5 V6 has 20k miles.
The dash counter says air filter is at 35%.

I never went more than 12k on one.
Im changing it now.

Just wondering how accurate these things are. Hate to waste money if i can get another year out of it lol

It looks clean and i can blow it out if need be

 

[PBGas]

Are you talking the engine air filter or the cabin filter?

Either way, you might as well just change it for piece of mind. Usually these things are calculated by engine run time.