What you enter is not “hours.” It is a workday.
Every calculator on this site takes the same three facts a wage order actually cares about: when you punched in, when you punched out, and how many minutes of unpaid lunch sat in the middle. You can add a second (or third) shift on the same day. The engine then does two different measurements.
Hours worked is the sum of the shifts minus unpaid lunch. That figure feeds overtime and double time. Span is first punch to last punch, including the lunch and every gap between splits. New York hospitality pays on the span. California overtime pays on the hours. Using one number for both is how people underpay a split shift.
What this site will not do
It will not invent on-duty meal agreements or Brinker timing charts. Miscellaneous-industry call-in and split/spread live on their own 12 NYCRR 142 page; they are not folded into hospitality 146. Alternative workweeks live on their own Labor Code 511 page; they are not folded into the LC 510 default. If a rule is not on the page, it is not in the math. Each calculator stamps its scope in plain language so a search snippet and a human being get the same story.