Size matters.
Single wick candles are mostly small and medium candles.
4-8oz candles are considered small sized and are great for bathroom/laundry room.
8-10oz candles are considered medium sized. These are great for bedrooms/ similar sized rooms.
Large candles contain 2-4 wicks. These are great for the living room/ kitchen area. Larger candles have bigger melt pools and stronger scent throw.