This page shows some common transom window sizes and common number sizes. This will help you decide exactly what height numbers you should choose. Still can't decide? Fear not ... you can select the option to get a mock up and work with one of our designers to ensure all the sizing looks just right.
Window Size: 30" wide x 10" high
Number Size: 5" high
Window Size: 30" wide x 15" high
Number Size: 7" high
Window Size: 36" wide x 20" high
Number Size: 9" high