Filter King Merv 8 12x36x2 12-Pack Air Filter actual size is 11.5x35.5x1.75. Our 12x36x2 Furnace Filters are designed to last up to 90 days. These pleated 2-inch air filters are ideal for maintaining the efficiency of your heating and cooling systems. Make sure you measure your filter. The actual size of this pleated Merv 8 filter is 11-1/2 x 35-1/2 x 1-3/4