It's so hard to know. DD always had a huge afternoon sleep of around 3 hours and sometimes until 5pm and would still go to bed at 7.30pm and sleep for 12 hours.

She did that until she was at least 2.

I thought, though, that 'they' reckoned most babies/toddlers need a similar amount of sleep overall. Some get some of it through a long day sleep and a shorter night sleep whereas others will get it with a shorter day sleep and longer night sleep.

Dunno TBH.