The amount of shrinkage a cotton shirt experiences after drying can vary depending on various factors such as the fabric quality, initial sizing, washing and drying methods, and individual characteristics of the shirt. Generally, cotton fabric has a tendency to shrink when exposed to heat.
Pre-shrunk cotton shirts, which have undergone a shrinking process during manufacturing, are designed to minimize further shrinkage. However, non-pre-shrunk cotton shirts can still shrink to some degree. On average, you can expect a cotton shirt to shrink between 3% to 5% in length and width after the first wash and dry.
It's important to note that different brands and fabric compositions may have slightly different shrinkage rates. To minimize shrinkage, it's advisable to follow the care instructions provided by the manufacturer and avoid using high heat during the drying process.