Between the same brands yes, but the measurements are exactly like mountain bike tire sizes. No standard between different companies. There are some tires that measure out to be the exact size, and there are other others that are over but are called that size and there are some that are called that size, but ar smaller.

For example a 2.5 highroller is more like 2.35 and a 2.5 michelin is more like a 2.7