Does anyone have any numbers for the average lifespan of a garment? Seems best to measure it in terms of number of washes before it would have to be retired.
Now what someone considers a no longer wearable garment is subjective so I understand some answers will have some variance but my guess is that there has to be a general number.
So any numbers on general t-shirts such as Haynes beefy-t, Gildan, etc mid weight 5.5oz shirts?
And high end American Apparel, Anvil 980, etc 4.5oz shirts?
I think it would depend on how the shirts are handled. Hot water and a hot drier are going to effect the fabric differently than cold water and a warm drier. The detergent, any use of bleach, even the type of water will make a difference. Notice the difference in the life span of shirts you send to the laundry - they don't last nearly as long as the shirts you wash at home. It is more in the handling of the shirt than in the brand.
I think it would depend on how the shirts are handled. Hot water and a hot drier are going to effect the fabric differently than cold water and a warm drier. The detergent, any use of bleach, even the type of water will make a difference. Notice the difference in the life span of shirts you send to the laundry - they don't last nearly as long as the shirts you wash at home. It is more in the handling of the shirt than in the brand.
That is a very good point, I forgot to add using garments recommended washing instructions. Type of detergent and bleaches are probably as varied as it can get so I will just have to suck that one up as unknowable.
The reality is probably the average consumer uses the cheapest on sale detergent and dries on high heat. People who care about their garments I would venture to guess are in the minority, only giving special care to the most expensive garments in their wardrobe.
An addendum to the questions would be lifespan in best and worst case scenarios
Garment lifespan 
