To center it, I had to use my mad math skillz. =) 31.5 inches in half is approximately 15.5 inches. I measured 15.5 inches in. The total height of the birdcage is 25 inches (subtract from 37.5 inches) and you are left with 12.5 inches. Divide 12.5 inches in half which is 6 (and something) inches. I measured 6 inches down from the halfway point. Make sense?