I'm 180 lbs sit on a standard 5-leg office chair. Mat sits on a 1/4" deep wall to wall rug.Sitting still 15 minutes at desk leaves a dimple under front wheels that's difficule to roll out of. Totally unsatisfactory. I have already ordered a replacement(tempered glass). It's like the plastic wasn't cured. My previous mat was thinner and totally satisfactory but too small(3x4)- kept rolling of the edges. This one is almost 50% thicker(0.1 vs 0.145) but much less supportive. I was suprised - and dissappointed.
Not as heavy as advertised on the tag in the store had to order one to be delivered this mat will fail in about a year. Deflects heavily on a medium pile rug. Check them out before you buy one.