Punch Clock MathHours, overtime and every state’s rules

Time cards & hours · calculator

Add hours and minutes

A column of hours and minutes — added, or taken away — with the total in h:mm and in decimal hours.

Your hours

Example
48:5848.97 hours6 rowsFull result
Type the hours as
  1. Running total 8:06
  2. Running total 18:21
  3. Running total 26:01
  4. Running total 36:31
  5. Running total 44:28
  6. Running total 48:58

Each row shows the running total so far (beside the row, or under it on a narrow screen). Tap + or − to switch a row between adding and subtracting.

Try an example

Total

48:5848.97 hours

48 hours 58 minutes

8:06 + 10:15 + 7:40 + 10:30 + 7:57 + 4:30 = 48:58

Added in minutes (2,938 minutes), then converted once: 2,938 ÷ 60 = 48.97 hours.

Total 48:58, 48.97 hours.

RuleEach row is turned into whole minutes; the rows are added in minutes; the total is converted once (minutes ÷ 60, half up to the hundredth)Sources checked How the math works ↓

The rows to scale

one hour axis
Added · 48:58123456Total48:5801020304050 h

Scale: 1 hour = 6.8 px · numbers are the rows

The minutes past 48 whole hours

Minutes · 60 in an hour015304560 min0.25.50.751.00 h58 min = .97 hHundredths · 100 in an hour

Scale: both rulers are one hour long · 1 minute = 5.6 px · 0.01 h = 3.4 px

Calculated with Punch Clock Math · rules checked October 22, 2026 · an estimate, not legal or tax advice · punchclockmath.com

How the math works

Hours and minutes don’t add like ordinary decimals: 60 minutes carry into one hour.

  1. Turn each row into minutes8:06 = 8 × 60 + 6 = 486 minutes.A decimal row becomes the nearest whole minute: 7.3 hours = 438 minutes (7:18).
  2. Add and subtract in minutes486 + 615 + 460 + 630 + 477 + 270 = 2,938 minutes.A row marked − is taken away: 40:00 − 38:45 = 2,400 − 2,325 = 75 minutes.
  3. Back to hours and minutes2,938 ÷ 60 = 48 hours, 58 minutes left → 48:58.
  4. Convert to decimal once2,938 ÷ 60 = 48.966… → 48.97 hours.Adding already-rounded decimals instead can drift by a hundredth or more over a long column, so the total is always added in minutes first.

What this doesn’t cover

  • Clock times: this adds lengths of time. To get the hours between a start and an end time, use the hours calculator.
  • Overtime: a total over 40 hours is not split into overtime here; the time card calculator applies the weekly and state rules.
  • Seconds: durations are whole minutes; seconds are not modeled.

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