Convert a clock duration into decimal hours and back again.
Converting through total seconds handles all three components uniformly and avoids compounding rounding at each step. The fraction of a day is what spreadsheet date arithmetic uses internally. Spreadsheets store times as fractions of a day, which is why a duration pasted as text so often produces nonsense until converted properly.
Hours to Decimal
Decimal hours = (hours × 3,600 + minutes × 60 + seconds) ÷ 3,600
Decimal hours = (hours × 3,600 + minutes × 60 + seconds) ÷ 3,600 Converting through total seconds handles all three components uniformly and avoids compounding rounding at each step. The fraction of a day is what spreadsheet date arithmetic uses internally.
Spreadsheets store times as fractions of a day, which is why a duration pasted as text so often produces nonsense until converted properly.
This calculator takes 3 inputs: Hours, Minutes, Seconds. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.