The 7 percent solution. When sizing a baseboard in a traditional-style home, a good starting point is to use a ratio of 7 percent. So if your ceiling height is 8 feet high, try a baseboard that's about 7 inches tall.
4. How to Size Interior Trim for a Finished LookTrim is often subtle, unless it's done wrong. For Houzzers who love traditional, modern or contemporary looks, these guidelines offer trim recommendations and solutions for all home styles.