Toilet Seat Measurements Are Toilet Seats A Standard Size Or Do I Need Specific Measurements?

Are toilet seats a standard size or do I need specific measurements? - toilet seat measurements

Yesterday, my two years old son who is about to begin the potty training and is very interested in "Big Bad", was the seat down too fast and broke. I want to replace it, but I am not satisfied with the renovation. You can go directly to Wal-Mart and select a standard size or are there specific measures that produce? I live in an apartment building. You think I am the owner / maintenance before replacing or not really a factor?