noun
splitting equally; sharing equally
Used for dividing costs, profits, or other amounts evenly among participants, often on a per-person basis.
飲み会の費用は頭割りにしましょう。
Let's split the cost of the drinking party equally.
利益は全員で頭割りにした。
We divided the profits equally among everyone.
割り勘 specifically refers to splitting a bill (usually at a restaurant or bar), while 頭割り is a broader term for equal division of any amount.
Compound of 頭 (head, person) and 割り (splitting), literally 'per-head splitting'.