Hours Calculator: Time Between Two Times
Count hours and minutes between any two times. Work shifts, billable time, sleep duration. 12-hour, 24-hour and military time all work. Optional break subtraction.
Common Hour Calculations at a Glance
Some of the most-searched time spans, pre-calculated. Drop your own times into the calculator above for anything not listed.
| From | To | Hours | Decimal |
|---|---|---|---|
| 9:00 AM | 5:00 PM | 8 h 0 min | 8.00 |
| 8:00 AM | 4:30 PM | 8 h 30 min | 8.50 |
| 8:30 AM | 5:00 PM | 8 h 30 min | 8.50 |
| 9:00 AM | 12:00 PM | 3 h 0 min | 3.00 |
| 7:00 AM | 3:30 PM | 8 h 30 min | 8.50 |
| 23:00 (11 PM) | 07:00 (7 AM) | 8 h 0 min | 8.00 |
| 14:15 (2:15 PM) | 22:45 (10:45 PM) | 8 h 30 min | 8.50 |
These assume zero break time. With a standard unpaid 30-minute lunch, subtract 0.50 from the decimal column to get paid hours.
Quick Answers: The Most-Searched Time Spans
People type these spans into search engines thousands of times a day. Here they are, pre-calculated. The rule behind every row: convert both times to minutes since midnight, subtract, and add 24 hours if the span crosses midnight.
| Span | Hours | Span | Hours |
|---|---|---|---|
| 10 AM to 5 PM | 7 h | 10 AM to 4 PM | 6 h |
| 10 AM to 8 PM | 10 h | 11 AM to 9 PM | 10 h |
| 12 PM to 8 PM | 8 h | 12 PM to 9 PM | 9 h |
| 2 PM to 8 PM | 6 h | 2 PM to 11 PM | 9 h |
| 2 PM to 2 AM | 12 h | 12 AM to 8 AM | 8 h |
| 2 PM to 10 PM | 8 h | 2 PM to 5 PM | 3 h |
| 2 PM to 6 PM | 4 h | 2 PM to 7 PM | 5 h |
Half-hour starts and ends
Spans that start or end on the half hour trip people up because the minutes need borrowing. Worked the same way: minutes since midnight, then subtract.
| Span | Hours | Span | Hours |
|---|---|---|---|
| 10:30 to 2:30 | 4 h | 10:30 to 3:00 | 4 h 30 min |
| 10:30 to 4:00 | 5 h 30 min | 10:30 to 6:00 | 7 h 30 min |
| 11:30 to 1:00 | 1 h 30 min | 11:30 to 3:30 | 4 h |
| 11:30 to 6:00 | 6 h 30 min | 12:30 to 2:30 | 2 h |
| 1:30 to 4:30 | 3 h | 8:30 to 5:00 | 8 h 30 min |
| 0830 to 1700 | 8 h 30 min | 0800 to 1600 | 8 h |
The 12-hour spans above assume the obvious reading (10:30 AM to 2:30 PM, not a 16-hour overnight). For overnight spans, enter the times in the calculator and it adds the 24 hours for you.
From Daily Shift to Weekly Hours
Payroll runs weekly, so the daily number matters times five. With one unpaid 30-minute lunch per day:
| Daily Shift | Paid Hours/Day | Paid Hours/Week (5 days) |
|---|---|---|
| 8:00 to 4:00 | 7.5 | 37.5 |
| 8:00 to 4:30 | 8.0 | 40.0 |
| 9:00 to 5:00 | 7.5 | 37.5 |
| 9:00 to 5:30 | 8.0 | 40.0 |
| 7:00 to 3:30 | 8.0 | 40.0 |
This is why so many "9 to 5" jobs actually schedule 8:30 to 5:00 or 9:00 to 5:30. The extra half hour covers the unpaid lunch and brings the week to a full 40 paid hours.
For Time Sheets and Billing
The "decimal hours" field is the format most payroll and billing systems expect. Critical conversions:
| Clock Time | Decimal Hours |
|---|---|
| 8 h 15 min | 8.25 |
| 8 h 30 min | 8.50 |
| 8 h 45 min | 8.75 |
| 7 h 20 min | 7.33 |
| 7 h 40 min | 7.67 |
Don't enter raw clock time (8:30) into a decimal field — your hours will be 30% lower than intended. This is a common payroll error costing employees real money.
A 9 AM-5 PM shift isn't always 8 paid hours
Under U.S. Fair Labor Standards Act (FLSA) rules:
- Breaks under 20 minutes — must be paid (count as work time)
- Meal breaks 30 min+ — typically unpaid if employee is completely free of duties
- "Half-hour at desk eating while monitoring email" — must be paid (you're still working)
A standard 9-5 schedule with a 30-min unpaid lunch = 7.5 paid hours, not 8. Over a year (52 × 5 days), that's ~130 hours of unpaid time. State laws often add more protection — California, for example, requires paid 10-min breaks every 4 hours.
Crossing Midnight
If your end time is before your start time (e.g., 23:00 to 07:00), the calculator assumes you crossed midnight and adds 24 hours. Useful for overnight shifts, but verify if you have a split shift or multi-day calculation.
Time Format Standards
- 24-hour format (ISO 8601): 14:30 = 2:30 PM. Used by most of the world and all programming systems.
- 12-hour format (AM/PM): 2:30 PM. Used by most U.S. consumer-facing displays.
- Noon and midnight: Strictly speaking, "12 PM" is ambiguous; ISO 8601 uses 12:00 (noon) and 00:00 (midnight) to remove ambiguity.
Frequently Asked Questions
How many hours from 9 to 5?
9 AM to 5 PM is exactly 8 hours. Subtract any unpaid breaks. A standard 30-minute lunch makes it 7.5 paid hours; a 60-minute lunch makes it 7 paid hours.
How many hours is 10:30 to 2:30?
10:30 AM to 2:30 PM is exactly 4 hours. The minutes match (both :30), so you can subtract the hours directly: 14:30 minus 10:30 = 4:00. When the minutes differ, convert to minutes since midnight first: 10:30 = 630 min, 3:00 PM = 900 min, difference 270 min = 4 h 30 min.
How many hours is 2 PM to 2 AM?
12 hours. The span crosses midnight, so add 24 hours to the end time: 2 AM becomes 26:00, minus 14:00 = 12 hours. Any span where the end clock reads earlier than the start works this way.
How do I calculate hours in military time?
Military time uses 00:00 to 23:59 (no AM/PM). Subtract the start from the end. Example: 14:30 minus 09:00 = 5 hours 30 minutes. If the end is smaller than the start (overnight shift like 22:00 to 06:00), add 24 hours, then subtract.
What is 2.75 hours in hours and minutes?
2.75 hours = 2 hours and 45 minutes. The decimal fraction multiplies by 60: 0.75 × 60 = 45 minutes. Same logic for any decimal: 0.25 = 15 min, 0.33 = 20 min, 0.50 = 30 min, 0.67 = 40 min, 0.75 = 45 min.
How do I add hours up across the day?
Convert each segment to decimal hours, then add. Or use the calculator multiple times and sum the results. The mistake to avoid: adding raw clock-time numbers (8:30 + 7:45 is not 16:15 — minutes don't carry like 100s).
How do I handle hours that cross midnight?
If the end time is earlier than the start (e.g., 23:00 to 07:00), assume you crossed midnight and add 24 hours to the end. The calculator above does this automatically.
What's "overtime" in the U.S.?
Federal FLSA defines overtime as hours over 40 in a workweek, paid at 1.5× regular rate. Some states have daily overtime (California: 1.5× after 8 hours/day, 2× after 12). Salaried employees above ~$43,888/year (2024) are typically exempt.
Do I round time?
Many timesheets round to the nearest 15 minutes (quarter-hour). Federal law (29 CFR § 785.48) allows rounding only if it doesn't systematically favor the employer. Common practice: round to nearest 0.25 hour for billing.