What size toilet seat should you buy? Toilet seats are made in two different sizes: ROUND (standard measurement of 16.5") ELONGATED (standard measurement of 18.5") What size bow! do | have? Measure your toilet from front of bow! to mounting holes. 16.5 in 43 em ROUND 16.5 in (STANDARD) 42 cm v Kinsey ROUND toilet seats fit most ROUND bowls. | ELONGATED | 4 18.51 47 em 2 Sin T Kinsey ELONGATED toilet seats fit most ELONGATED bowls.
