Hours Calculator – Hours Between Two Times or Dates

How to Calculate Hours Between Two Times

Convert each clock time to minutes past midnight, subtract the start from the end, then split the difference back into hours and minutes. 8 hours 00 minutes pass between 9:00 AM and 5:00 PM. If the end clock is earlier than the start, add 24 hours so an overnight span such as 10:00 PM to 6:00 AM is counted as 8 hours 00 minutes.

How to Use the Hours Calculator

1. Use Two times for a clock span on a generic day, including overnight. Use Two dates when the range covers more than one calendar day.
2. Set hours and minutes in 12-hour or 24-hour format. Use Now for the current local time. In date mode, pick start and end dates as well.
3. Hours, minutes, decimal hours, and total minutes update as you type. Overnight spans are labeled when the end clock is earlier than the start.
4. Copy the result for a log or spreadsheet. Open Time Duration Calculator for hours, minutes, and seconds, or Work Hours Calculator when you need break deductions.

Hours Between Two Times: Formula

startMinutes = startHour × 60 + startMinute

endMinutes = endHour × 60 + endMinute

durationMinutes = endMinutes − startMinutes

if durationMinutes < 0, durationMinutes += 1440

decimalHours = durationMinutes ÷ 60

Example: 8:30 AM is 510 minutes and 5:15 PM is 1,035 minutes. 1,035 − 510 = 525 minutes, which is 8 hours 45 minutes or 8.75 decimal hours. Equal start and end times are 0 hours, not 24, unless you set a later end date.

Hours Calculator Examples

• 9:00 AM to 5:00 PM → 8 hours 00 minutes (8.00 hours).
• 8:30 AM to 5:15 PM → 8 hours 45 minutes (8.75 hours).
• 10:00 PM to 6:00 AM → 8 hours 00 minutes (8.00 hours), next day.
• 9:45 AM to 4:25 PM → 6 hours 40 minutes (6.67 hours).
• Monday 9:00 AM to Wednesday 3:30 PM → 54 hours 30 minutes (54.50 hours) in date mode, when no daylight-saving change occurs in your timezone.

How to Convert Hours and Minutes to Decimal Hours

Decimal hours divide minutes by 60. 7 hours 45 minutes is 7.75 hours, not 7.45. The “.45” mistake treats minutes as hundredths. This table is a conversion aid, not a payroll rounding rule.

Calculating Hours Across Midnight

Clock mode assumes at most one midnight crossing. 10:00 PM is 1,320 minutes and 6:00 AM is 360 minutes. 360 − 1,320 is negative, so the calculator adds 1,440 minutes and reports 8 hours 00 minutes. 12:00 AM is midnight; 12:00 PM is noon. If the end is earlier because you mixed up AM and PM, the same overnight rule still applies — check the period before you copy the result.

How to Calculate Hours Between Two Dates

Use date mode when the span covers more than one midnight, such as Monday 9:00 AM to Wednesday 3:30 PM (54 hours 30 minutes / 54.50 hours when the local clock does not change for daylight saving). Date mode subtracts local Date timestamps in this browser. That is actual elapsed time in your timezone, not a timesheet rule and not a conversion between two named time zones. Ambiguous or skipped DST clock times follow whatever the browser Date object does; this page does not claim a custom DST engine.

Common Hours Calculation Mistakes

• Reading 12:00 AM as noon, or 12:00 PM as midnight.
• Leaving PM on a morning end time, which can look like an overnight span.
• Writing 7 hours 45 minutes as 7.45 decimal hours instead of 7.75.
• Using clock mode for a Monday-to-Wednesday range instead of date mode.
• Treating equal start and end times as a 24-hour day. This calculator returns 0 unless you set a later end date.
• Expecting unpaid lunch to come off automatically. This page is gross elapsed time. Use the Work Hours Calculator for paid hours after breaks, including what used to live on Hours Calculator with Break and Shift Hours Calculator.
• Assuming every timezone or DST change is applied the same way as a payroll system.

Hours Calculator vs Related Time Tools

This Hours Calculator owns gross elapsed hours between two times or two date-times. It does not subtract breaks and it does not split overtime.

• Hours Calculator — clock or date-time difference in hours, minutes, and decimal hours.
• Work Hours Calculator — paid work hours, weekly totals, and break deductions. Overnight shifts with lunch belong here.
• Hours Calculator with Break / Shift Hours — those older URLs redirect to Work Hours Calculator. Subtract a lunch from one shift there.
• Time Duration Calculator — elapsed time with hours, minutes, and seconds, including overnight timestamps.

Frequently Asked Questions

Related Calculators

• Find the time between two dates — Elapsed hours, minutes, and seconds between two timestamps.
• Calculate paid work hours after breaks — Net shift and weekly hours after unpaid break deductions.
• Add or subtract time from a clock — Move a start time forward or backward by a duration.
• Add or subtract calendar days — Date arithmetic when you care about the calendar, not clock hours.

Trust and Methodology

Clock mode uses integer minutes past midnight and adds 1,440 minutes for one overnight wrap. Date mode uses local Date objects in your browser. Inputs are not uploaded for the calculation itself. This is elapsed time, not legal, payroll, or timesheet advice. Employer rounding rules can differ.