Filter King Merv 8 9x11.75x1 2-Pack Air Filter actual size is 9x11.75x.75. Our 9x11.75x1 Furnace Filters are designed to last up to 90 days. These pleated 1-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 9 x 11-3/4 x 3/4