While it depends on the size and style of the shirt, 2.75 yards of fabric can usually make a comfortably large long-sleeved shirt for an average-sized woman, and men's shirts will require about 15 percent more fabric. A simple T-shirt for a small child can be made with 1 yard of fabric.
Fabric is sold at the store in square yards. One yard is equal to 3 feet, so a 2-yard section of fabric will be 6 feet by 3 feet. When purchasing fabric for sewing a shirt, it is always a safe bet to buy slightly more than the shirt will actually need. Women's shirts can usually be made using less than 3 yards of fabric, and men's shirts of the same style will require a bit more fabric as men are typically a little larger than women.