When measuring your stairs, if the carpet is still installed, and the existing bullnose still in tact, the measurements you have may not be as accurate for your new stair tread installation.
If you have completed all of the above, and still have steps that are larger in width (front to back) than our standard 11 1/2", there are some solutions!
You can visit our Over Sized Stair Tread page by clicking the link below.
Over Sized Stair Treads:
http://www.stair-treads.com/moulding-and-accessories/oversized-stair-treads.html
However, what you are looking for may not be listed on that page. In that case, please call and speak to one of our friendly representatives who will be happy to talk to you, and help you get the right size, specie, and stained tread that you desire. You can reach a knowledgeable team member at our toll free number 866-429-0979.