Measure 45 inches up from the floor and mark the side wall horizontally. This is the amount of space necessary to hang shirts, pants (folded in half) suits, blouses and skirts. The only things that won't fit in this space are street dresses and longer coats.
Measure 12 inches out from the back wall, along the 45-inch line you created in Step 1. You'll install the hardware on which to hang the lower closet rod at this point. Repeat the same measurements for the opposite side of the closet.
Place your measuring tape at the floor of the closet and measure up 90 inches. Mark the side wall at the 90-inch height for the second rod. This is just a little more than the standard reach for a person of 5 feet, 8 inches.
Measure 12 inches out from the back wall, along the 90-inch line you drew in Step 3. This point is where you'll place your second rod in the two tiered closet. Repeat the process on the opposite side wall.