Minimum tread depth for all 4 tires is 2/32"
On or before your country's legal minimum requirement for tread. If in doubt see out a qualified fitter to check the tread depth for you
The minimum tread depth in New York is 2/32". U.S.- and European-manufactured tires have wear bars or tread wear indicators molded into the tread. There are portions of the tire that are raised 2/32". When the tread wears down so the tires are no longer legal, these portions will form a smooth bar across the tire in several places.
60% tread wear.
The minimum tyre tread depth in the UK is 1.6mm.
Slow down and make sure your tires have at least 2/32" of tread depth.
In Virginia you must have 2/32 tread depth on all 4 tires to pass inspection.
When your tires have 2/32" tread depth left you need to replace them.
That depends on who old/used the type is.
I inspect the tire and measure the tread depth.
It varies from state to state. In most states it is 2/32" but in some it is 3/32".
In the United States, the tread has to be 4/32 (3.17mm) or more on the front tires and 2/32 (1.58mm) or more on the back tires. rear tires can be retreaded but not the front "steer" tires.