#tip

Work out tips and split a bill — with exact cent maths so the per-person amounts always add back up to the total, no penny ever lost to rounding. The calc endpoint takes a bill, a tip percentage (15% by default) and a number of people and returns the tip amount, the grand total, the per-person amount, the effective tip percentage, and — when you want a tidy number — an optional rounding of the total either up to the next whole unit or to the nearest. When the bill does not divide evenly it produces a fair share list where a few people pay one cent more, so the parts sum precisely. The split endpoint divides any amount, optionally adding a tip first, evenly among people and returns that exact per-person share list. Everything is computed in integer cents locally and deterministically, so it is instant, private and always balances. Currency-agnostic — the numbers work for any currency. Ideal for restaurant and POS apps, expense-sharing and group-payment tools, delivery and service apps, and everyday bill splitting. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This calculates tips and splits; for percentage maths in general use a percentage API and for invoicing margins use a margin API.

api.oanor.com/tip-api