To determine the age of a piano by its serial number, check a piano reference guide, such as the Bluebook of Pianos, or with the piano's manufacturer. Pianos often have other figures, such as part or patent numbers, which may lead to confusion.
Serial numbers on pianos typically include information on the age of the piano and sometimes the location of manufacture. Piano manufacturers, such as Yamaha and Steinway, provide serial number and age information about their pianos on their websites. Steinway also offers additional information about the history of its pianos by serial number for a fee.
If the manufacturer is no longer in business or does not provide serial number information on their website, a piano reference guide is another useful resource. The website for the Bluebook of Pianos provides a list of serial numbers by manufacturer and the corresponding age of the piano. The e-book version of the Bluebook of Pianos also provides information on the value of new and used pianos.
Not all pianos can be dated to a specific year and the age may be more general, and some pianos made specifically for major retailers do not have a serial number, which makes them more difficult to date. For these pianos, consult a piano expert or post photos to a piano-related forum for help from piano enthusiasts.