Time Duration Calculator | Hours & Minutes Between Times

Q: How do I calculate hours and minutes between two times?

Enter your start and end times using the time pickers. The calculator automatically computes the exact difference and displays it in three formats: human-readable, decimal hours, and total minutes. It automatically handles cross-midnight durations.

Q: How do I add up multiple time durations for a timesheet?

Switch to the Accumulate Timesheet tab. Add each work segment by setting start/end times and clicking Add Segment. The calculator maintains a running total across all segments.

Q: How do freelancers track and bill hourly time?

Freelancers typically track time then round to agreed-upon increments (commonly 15 minutes for creative, 6 minutes for legal). The decimal hours output can be directly multiplied by your hourly rate.

Q: How do I round time to the nearest 15 minutes?

Use the quick-round buttons next to each time input. Click 15m to snap to the nearest 15-minute mark following standard mathematical rounding rules used in payroll and billing systems.

How to Use the Time Duration Calculator

1
Choose your mode. Use Single Duration to calculate the hours and minutes between one start and end time — perfect for a single work session. Switch to Accumulate Timesheet when you need to add up multiple time segments, such as a full workday with breaks.
2
Enter your times. Use the time pickers to set start and end times. Need precision rounding? Click the 5m, 15m, or 30m buttons next to each input to snap to the nearest increment — essential for billable time tracking. For common work patterns, use the preset buttons like 8h workday or 7.5h European day.
3
Read your results in three formats. The result card shows the duration in human-readable format (e.g., 8h 30m), decimal hours (8.50 hours — ideal for timesheets and invoicing), and total minutes (510 minutes). All three update instantly as you change the times.

Time Rounding Guide for Freelancers

Rounding billable time is a standard practice in freelancing, consulting, and professional services — but doing it legally and consistently requires understanding the accepted conventions across industries and jurisdictions.

6-Minute Increments (Legal Standard)

The legal profession predominantly uses 6-minute billing increments, also known as tenths of an hour (0.1h = 6 minutes). This standard is codified in many bar association guidelines and is accepted by courts when reviewing attorney fee petitions. A 6-minute minimum means a 2-minute phone call rounds to 0.1 hours. This granularity ensures clients are billed only for substantive work while giving attorneys a practical unit for time tracking.

15-Minute Increments (Creative & Consulting)

Creative agencies, design studios, and management consultants commonly use 15-minute billing increments (0.25 hours). This strikes a balance between administrative overhead and billing accuracy. For example, a 40-minute client call is typically rounded to 45 minutes (0.75 hours). Many contracts explicitly state this rounding convention to avoid disputes. When in doubt, always round in the client's favor to maintain trust.

Clock-In / Clock-Out (Manufacturing & Retail)

Hourly workers in manufacturing, retail, and hospitality typically use exact clock-in/clock-out systems, often rounded to the nearest minute or 5-minute increment per labor regulations. The FLSA in the United States permits rounding to the nearest 5, 10, or 15 minutes provided it averages out fairly over time — meaning the rounding policy must not systematically underpay workers.

Quick Conversion Reference

Decimal Hours	Minutes	Common Use
0.25	15 min	Quarter-hour billing
0.50	30 min	Half-hour increment
0.75	45 min	Three-quarter hour
0.10	6 min	Legal minimum unit
0.17	10 min	Approximate 1/6 hour
1.00	60 min	One full hour

How Time Tracking Differs by Industry

Legal: The legal industry operates on strict 6-minute billing increments, often mandated by bar associations and client engagement letters. Lawyers record time in tenths of an hour (0.1h per 6 min) using specialized timekeeping software. Every phone call, email review, and document draft gets a time entry. This granularity is non-negotiable for court-awarded attorney fees.

Creative & Consulting: Agencies and consultants prefer 15-minute increments as the sweet spot between precision and practicality. A brainstorming session, client revision round, or research block is rounded to the nearest quarter hour. Detailed timesheets support retainer tracking and project profitability analysis.

Manufacturing & Retail: These industries rely on physical or digital punch clocks that record exact clock-in and clock-out times. Labor laws heavily regulate rounding practices — the FLSA requires any rounding system to be neutral over time. Payroll systems then convert raw hours into pay calculations with overtime rules.

Software & Tech: Time tracking in software varies dramatically. Some teams use sprint-based estimation (story points) rather than hourly tracking. Others track time for client billing or R&D tax credits. When tracking is required, tools like Harvest or Toggl capture granular time logs, but many developers resist micro-tracking in favor of broader daily summaries.

Decimal Hours Conversion

Converting minutes to decimal hours is essential for timesheet arithmetic. Since an hour has 60 minutes, divide minutes by 60 to get the decimal equivalent. For instance, 30 minutes divided by 60 equals 0.50 hours. This conversion is what payroll systems and invoicing tools use under the hood.

Minutes	Decimal	Minutes	Decimal
5 min	0.0833	35 min	0.5833
10 min	0.1667	40 min	0.6667
15 min	0.25	45 min	0.75
20 min	0.3333	50 min	0.8333
25 min	0.4167	55 min	0.9167
30 min	0.50	60 min	1.00

Frequently Asked Questions

How do I calculate hours and minutes between two times?

Enter your start and end times using the time pickers above. The calculator automatically computes the exact difference and displays it in three formats: human-readable (e.g., 5h 30m), decimal hours (5.50 hours), and total minutes (330 minutes). The calculator automatically handles cross-midnight durations — if your end time is earlier than your start time, it assumes the next day.

How do I convert hours and minutes to decimal hours?

Divide the number of minutes by 60. For example, 15 minutes / 60 = 0.25 hours. 30 minutes = 0.50 hours. 45 minutes = 0.75 hours. This calculator does the conversion automatically, providing decimal hours as one of the three output formats. For a complete reference, see the conversion table in the Decimal Hours Conversion section above.

How do I add up multiple time durations for a timesheet?

Switch to the Accumulate Timesheet tab. Add each work segment by setting the start and end time, then clicking "+ Add Segment". The calculator maintains a running total of all segments, with the sum displayed in all three output formats. You can delete individual segments or clear all at once. This is ideal for calculating total billable hours across a full day or week.

What is the difference between elapsed time and clock time?

Elapsed time measures the actual duration between two moments (e.g., 8 hours worked), while clock time refers to the specific time-of-day values (e.g., 9:00 AM to 5:00 PM). This calculator focuses on elapsed duration — it extracts the difference regardless of the clock values. This distinction matters for cross-midnight calculations and time zone considerations.

How do freelancers track and bill hourly time?

Freelancers typically use time tracking tools or manual timesheets, then round to agreed-upon increments (commonly 15 minutes for creative work, 6 minutes for legal). The decimal hours output from this calculator can be directly multiplied by your hourly rate: for example, 8.50 hours at $75/hr = $637.50. Consistent rounding practices, documented in your contract, help avoid client disputes.

How do I round time to the nearest 15 minutes?

Use the quick-round buttons next to each time input — click 15m to snap the selected time to the nearest 15-minute mark. The calculator rounds mathematically: times ending in :07 or less round down, :08 or more round up. For example, 9:07 rounds to 9:00, while 9:08 rounds to 9:15. This follows standard rounding rules used in payroll and billing systems.