Military Time Calculator
Add time, subtract time, or find the hours between two military times. Built for shift workers, nurses, dispatchers, and anyone who needs fast 24 hour math.
Time Difference Calculator
How many hours and minutes between two military times?
Add or Subtract Military Time
Add or subtract hours and minutes from any military time.
Shift Length Calculator
Calculate your total shift length, with or without a break.
How to Use the Military Time Calculator
This calculator handles three types of military time math that a simple converter can't do.
Time Difference
Enter a start time and an end time to see how many hours and minutes are between them. It works even when the times cross midnight, so 2200 to 0600 correctly returns 8 hours, not negative 16.
Add or Subtract Time
Start with any military time and add or subtract hours and minutes. Use it to find when a medication is due, when a shift ends, or when a flight lands. A flight that leaves at 1430 and takes 3 hours 45 minutes arrives at 1815.
Shift Length
Enter your shift start and end times, plus any break in minutes. You get the total shift length and the hours worked after the break. A nurse working 0700 to 1900 with a 30 minute break sees 12 hours total and 11 hours 30 minutes worked.
Why Military Time Math Is Different
On a regular 12 hour clock, the numbers reset at 12, so most people do the math without thinking. Military time runs from 0000 to 2359, and the math gets tricky in two situations.
Crossing midnight. If a security guard starts at 2200 and ends at 0600, you can't just subtract 2200 from 0600 and get a useful number. You have to account for the clock rolling past 0000. This calculator handles that automatically.
Minutes and hours combined. A shift from 0745 to 1615 isn't a clean hour to hour calculation. You need to handle the 45 minutes and the 15 minutes separately, then combine them. The calculator does this for you.
Who Uses Military Time Calculations
Nurses and Healthcare Workers
Medication schedules run on strict military time intervals. An antibiotic given every 8 hours starting at 0600 is due again at 1400 and then at 2200. Nurses use time math constantly for medication windows, shift handoffs, and charting. See military time for nurses.
Police Officers and Dispatchers
Incident timelines must be precise to the minute. How long was someone detained? How many minutes passed between the 911 call and the officer arriving? These numbers show up in every report and can be challenged in court.
Payroll and HR Departments
Shift workers in manufacturing, warehousing, security, and transportation often log hours in military time. Payroll teams subtract start times from end times, take out breaks, and handle overnight shifts that cross midnight.
Pilots and Flight Operations
Flight planning uses military time. Departure time plus flight time equals arrival time. A flight leaving at 0815 with a 4 hour 20 minute flight time arrives at 1235. Pilots do this math for every flight plan.
Military Personnel
Duty rosters, guard shifts, and operation timelines all need military time math. A patrol from 0200 to 0800 is a 6 hour rotation. A convoy leaving at 0430 with a 9 hour drive arrives at 1330.
Common Military Time Calculations
Here are some of the most common calculations, already solved.
- Standard 8 hour shift: 0800 to 1600 = 8 hours. With a 30 minute lunch, you worked 7 hours 30 minutes.
- 12 hour nursing shift: 0700 to 1900 = 12 hours. The 1900 to 0700 night shift is also 12 hours.
- Overnight security shift: 2200 to 0600 = 8 hours. 2300 to 0700 = 8 hours.
- Medication every 4 hours starting at 0600: next doses at 1000, 1400, 1800, 2200, and 0200.
- Medication every 8 hours starting at 0800: next doses at 1600 and 0000.
Quick Formulas
- Difference that doesn't cross midnight: subtract the start from the end. 1700 minus 0900 = 8 hours.
- Difference that crosses midnight: subtract the start from 2400, then add the end time. 2400 minus 2200 = 2 hours, plus 0600 = 8 hours total.
- Adding time: add the hours and minutes separately. If the minutes go past 59, carry 1 to the hours. If the hours go past 23, subtract 24 (you've rolled into the next day).
- Subtracting time: subtract the hours and minutes separately. If the minutes go below 0, borrow 1 hour and add 60 minutes. If the hours go below 0, add 24 (you've rolled back into the previous day).
Or just use the calculator at the top of this page and skip the math entirely. To look up a single time instead, use the converter on our military time chart.
Frequently Asked Questions
How do you calculate hours between two military times?
Subtract the start time from the end time. If the end time is smaller than the start time (the time crosses midnight), subtract the start from 2400 and add the end time. Or use the calculator above for instant results.
What is the time difference between 0700 and 1900?
12 hours. 1900 minus 0700 equals 1200, which is 12 hours and 0 minutes.
How do you add 3 hours to 2200 in military time?
2200 plus 3 hours equals 0100. The clock passes midnight (2400 or 0000) and keeps going into the next day. 22 plus 3 equals 25, minus 24 equals 01, so the answer is 0100.
How do you calculate an overnight shift?
If the shift starts at 2300 and ends at 0700, subtract 2300 from 2400 to get 1 hour, then add 7 hours to get 8 hours total. The shift length calculator handles this automatically.
Can I use this for payroll calculations?
Yes. Enter the shift start and end times, add any break minutes, and the calculator shows the total length, the hours worked, and the hours worked as a decimal (like 7.5) for timesheets. It works for overnight shifts too.
Can I type times with a colon, like 07:30?
Yes. The calculator accepts 0730, 730, 07:30, and 7:30. Use 24 hour times, so 4:30 PM is 1630.