The ShirtHelper
Below is a search engine which will help you find a shirt that fits you. It’s based on data I have collected on many different brands, including Brooks Brothers, Charles Tyrwhitt, Express, Kamakura, TM Lewin and Uniqlo. It works as follows:
The left side of the grey bars in the chart tell you the waist size, the right side tells you the chest size. Longer bars are shirts with more of a “drop” as the chest size is much larger than the waist size.  All sizes are inches.  For a relatively tight fitting shirt you will want the garment chest measurement four inches more than your chest body measurement; and the garment waist measurement three inches more than your waist body measurement.
For more detail on measuring yourself see the measuring guide.

Step 1 : Neck Size (inches)

Step 2 : Arm Length (inches)

Results: Waist (left side of bar) & Chest (right side of bar)

Grant Slim Fit
36 inches
38 inches
Buy from retailer