Hours Calculator – Time Worked
Calculate total hours worked between start and end times, with break deduction. Use this free online tool for instant, accurate results. No signup needed.
How to Calculate Hours Worked Between Two Times
Calculating the total time worked between a start time and end time involves converting both times to a common unit (typically minutes from midnight), subtracting the start from the end, subtracting any break time, and converting the result to hours and minutes.
Step-by-step example: Start time 9:30 AM, end time 5:45 PM, 30-minute lunch break.
- Convert start to minutes from midnight: 9×60 + 30 = 570 minutes
- Convert end to minutes from midnight: 17×60 + 45 = 1065 minutes
- Total elapsed minutes: 1065 − 570 = 495 minutes
- Subtract break: 495 − 30 = 465 minutes worked
- Convert to hours: 465 ÷ 60 = 7.75 hours = 7 hours 45 minutes
Overnight shifts (end time is earlier than start time): add 1440 minutes (24 hours) to the end time before subtracting. Example: 11:00 PM to 7:00 AM. Start = 23:00 = 1380 min. End = 7:00 = 420 min. Since 420 < 1380, add 1440: 420 + 1440 = 1860. Hours = 1860 − 1380 = 480 min = 8 hours.
Decimal Hours Reference Table
Payroll systems, billing, and project tracking often use decimal hours rather than hours and minutes. Here's the complete conversion table for minutes to decimal fractions of an hour:
| Minutes | Decimal Hours | Minutes | Decimal Hours |
|---|---|---|---|
| 5 min | 0.083 hrs | 35 min | 0.583 hrs |
| 10 min | 0.167 hrs | 40 min | 0.667 hrs |
| 15 min | 0.250 hrs | 45 min | 0.750 hrs |
| 20 min | 0.333 hrs | 50 min | 0.833 hrs |
| 25 min | 0.417 hrs | 55 min | 0.917 hrs |
| 30 min | 0.500 hrs | 60 min | 1.000 hrs |
To convert decimal hours back to hours and minutes: the whole number is hours; multiply the decimal portion by 60 to get minutes. Example: 7.75 hours → 7 hours + (0.75 × 60) = 7 hours 45 minutes.
Weekly Hours Tracking and Overtime Rules
Accurate time tracking is essential for hourly employees to ensure correct pay — including overtime premiums. Laws governing overtime vary by country and jurisdiction.
| Country/Region | Overtime Threshold | Overtime Rate | Notes |
|---|---|---|---|
| United States (FLSA) | 40 hrs/week | 1.5× | Some states have daily overtime |
| California | 8 hrs/day OR 40 hrs/week | 1.5× daily; 2× after 12 hrs/day | Most employee-protective US state |
| European Union | 48 hrs/week (average) | Varies by national law | Working Time Directive |
| United Kingdom | 48 hrs/week (opt-out possible) | Varies by contract | Can opt out with written agreement |
| Canada | Varies by province (40–44 hrs) | 1.5× | Ontario: 44 hrs; BC: 40 hrs |
Some US states have additional overtime rules beyond FLSA. California requires 1.5× pay for hours over 8 in a single day and 2× pay for hours over 12 in a day. Nevada has similar daily overtime provisions. Employers must follow whichever law (state or federal) provides greater protections to the employee.
Exempt employees (salaried workers classified as executives, administrators, or professionals earning over $684/week under FLSA) are not entitled to overtime pay regardless of hours worked. Misclassifying employees as exempt to avoid overtime is illegal and has resulted in significant class-action lawsuits.
Time Zones and Hours Calculation for Remote Teams
Global teams and remote workers often need to track hours across multiple time zones. This adds complexity because a meeting at 9 AM Eastern is 6 AM Pacific, 2 PM London, and 10 PM Tokyo (next day). When calculating billable hours for international clients, always clarify which time zone is being used.
Best practices for time zone management in remote work:
- Use UTC (Coordinated Universal Time) as the reference when logging time for international projects. UTC doesn't change with daylight saving time, eliminating a major source of confusion.
- Track work hours in local time for payroll purposes, but record the UTC offset. Example: 9:00 AM EST = 14:00 UTC; in summer (EDT) = 13:00 UTC.
- Be careful with DST transitions. In the US, clocks spring forward in March and fall back in November. A shift worked during the fall-back transition is technically 25 hours long for that one day.
- Time tracking software (Toggl, Clockify, Harvest) handles time zones automatically and generates accurate reports for payroll and billing.
Calculating Hourly Pay and Wages
Once you know the total hours worked, calculating pay is straightforward. For regular hours at a straight hourly rate:
Pay = Hours × Hourly Rate
With overtime (US): Pay = Regular Hours × Rate + Overtime Hours × (1.5 × Rate)
| Hours Worked | Hourly Rate | Regular Pay (40 hrs max) | OT Hours | OT Pay (1.5×) | Total Pay |
|---|---|---|---|---|---|
| 40 hrs | $20/hr | $800 | 0 | $0 | $800 |
| 45 hrs | $20/hr | $800 | 5 | $150 | $950 |
| 50 hrs | $20/hr | $800 | 10 | $300 | $1,100 |
| 60 hrs | $25/hr | $1,000 | 20 | $750 | $1,750 |
For salaried employees, hourly rate = Annual Salary / (52 × 40) or / (52 × average weekly hours). Example: $60,000/year ÷ 2,080 hours = $28.85/hour effective rate. This helps compare job offers and evaluate whether working extra unpaid hours is worth it at the implied hourly rate.
Timesheet Management and Labor Law Compliance
Employers are legally required to maintain accurate time records for non-exempt employees. The FLSA requires records of hours worked each workday and total hours per workweek. Records must be kept for at least 3 years (payroll records) and 2 years (timesheets and wage calculations).
Common timesheet mistakes to avoid:
- Rounding errors: Many employers round time to the nearest quarter-hour, which is legal only if the practice averages out over time and doesn't systematically shortchange employees.
- Off-the-clock work: Requiring employees to work before clocking in, during lunch, or after clocking out — even briefly — is an FLSA violation. All hours worked must be compensated.
- Auto-deducting lunch breaks: If an employee is interrupted during lunch and performs work, the break is not truly unpaid. Best practice: have employees manually clock out and in for breaks.
- Failing to count travel time: Under FLSA, travel time between work sites during the day is compensable. Normal commuting (home to work) is not compensable, but travel required by the job (driving clients to appointments, traveling between two offices) generally is.
Part-Time Hours, Benefits Thresholds, and ACA
Under the Affordable Care Act (ACA), employees working 30+ hours per week on average are considered "full-time" and large employers (50+ full-time equivalent employees) must offer them health insurance or pay a penalty. This threshold has significant implications for employers managing part-time schedules.
Many benefits have hours-based thresholds:
| Benefit | Common Hours Threshold | Notes |
|---|---|---|
| ACA health insurance mandate | 30 hrs/week | Large employer requirement |
| FMLA eligibility | 1,250 hrs in past 12 months | ~24 hrs/week for a full year |
| ERISA pension eligibility | 1,000 hrs/year | ~19 hrs/week |
| Paid sick leave (California) | Accrues for all employees | Even part-time workers accrue |
| Full-time employment classification | 35–40 hrs/week | Varies by employer policy |
Tracking hours precisely helps both employees and employers stay compliant with these thresholds and ensure proper benefit eligibility determination. An employee who believes they should qualify for FMLA or ACA benefits can use their time records to verify eligibility.
Frequently Asked Questions
How do I add up multiple time intervals?
Convert each interval to decimal hours (minutes ÷ 60), sum all the decimals, then convert back. Example: shifts of 3h 45m, 4h 30m, 6h 15m. Decimals: 3.75 + 4.5 + 6.25 = 14.5 hours = 14 hours 30 minutes. Alternatively, add the hours and minutes separately: hours: 3+4+6=13; minutes: 45+30+15=90 min = 1h 30m. Total: 13 + 1 = 14 hours 30 min.
How do I account for breaks?
Subtract break time from the total elapsed time. If you worked 9:00 AM to 5:30 PM (8.5 hours elapsed) with a 30-minute unpaid lunch, paid hours = 8.5 − 0.5 = 8.0 hours. Note: paid vs unpaid breaks vary — the FLSA requires that short breaks (5–20 minutes) be paid; meal breaks of 30+ minutes where the employee is completely relieved of duty can be unpaid.
What if my shift crosses midnight?
Add 24 hours (1440 minutes) to the end time if it's smaller than the start time. Example: 11 PM to 7 AM. Start: 23:00 (1380 min). End: 7:00 (420 min). Since 420 < 1380, treat end as 7:00 + 24:00 = 31:00 (1860 min). Hours = (1860 − 1380) ÷ 60 = 8 hours.
How many hours is a typical work year?
A standard US full-time work year is 2,080 hours (52 weeks × 40 hours). Accounting for 10 federal holidays: 2,080 − 80 = 2,000 hours. With 2 weeks vacation (80 hours): 2,000 − 80 = 1,920 hours. Salary-to-hourly conversion: divide annual salary by actual working hours. $50,000 ÷ 1,920 hours ≈ $26.04/hour effective rate (including vacation).
How do I convert hours to a fraction of a day?
Divide hours by 24. 8 hours = 8/24 = 1/3 of a day. 6 hours = 1/4 of a day. 12 hours = 1/2 day. This is used in some billing systems and project management tools that track time as fractions of work days. A standard 8-hour work day = 1 "work day" unit in project management software.
What is the difference between clock hours and decimal hours?
Clock hours use the 60-minute system (7:45 means 7 hours and 45 minutes). Decimal hours use base 10 (7.75 means 7 hours and 45 minutes, because 45/60 = 0.75). Payroll calculations use decimal hours for arithmetic. 7:45 + 3:30 = 11:15 (clock) = 7.75 + 3.5 = 11.25 decimal hours. Always convert to decimal before multiplying by an hourly rate.
How do I calculate overtime pay for a partial workweek?
Under FLSA, overtime is calculated on a workweek basis (a fixed recurring 168-hour period). The first 40 hours in that workweek are straight time; hours 41+ are overtime. If you worked 45 hours in one week and 35 in the next, you earn 5 hours of OT in week 1 but no OT in week 2 — the weeks don't average together.
Can my employer require me to work overtime?
In most US states (at-will employment states), yes — employers can require overtime and terminate employees who refuse, unless protected by a union contract or specific state law. However, the employer must pay the proper overtime rate for all hours over 40. Some states (like California) have specific rules about mandatory overtime scheduling in certain industries like healthcare.
How does the calculator handle 24-hour (military) time?
Use the format HH:MM where hours go from 00 to 23. Midnight is 00:00, noon is 12:00, 1 PM is 13:00, 11 PM is 23:00. This format eliminates AM/PM ambiguity and is required for overnight shift calculations to work correctly.
How do I track hours for freelance billing?
Use decimal hours rounded to the nearest 0.1 or 0.25 hour for cleaner invoices. Log start and end times, subtract non-billable breaks, and multiply by your hourly rate. Many freelancers use time tracking apps (Toggl, Harvest, Clockify) that automate this process. Keep detailed records — they support invoices if clients dispute charges.
Historical Timekeeping and the Modern 8-Hour Workday
The 8-hour workday is a relatively modern concept. During the Industrial Revolution, 12–16 hour workdays were standard for factory workers, including children. The labor movement fought for decades to establish the "8 hours labor, 8 hours recreation, 8 hours rest" ideal promoted by Robert Owen in 1817.
Henry Ford famously adopted the 8-hour, 5-day workweek at Ford Motor Company in 1914, paying double wages — not out of altruism, but because he found it increased productivity and reduced turnover. The US Congress codified the 40-hour workweek through the Fair Labor Standards Act of 1938.
Today, research consistently shows that productivity per hour decreases significantly beyond 50–55 hours per week. A study by John Pencavel at Stanford found that output at 70 hours differed little from output at 55 hours — those extra 15 hours produced essentially nothing. Yet many knowledge workers regularly work 50+ hours. Tracking actual productive hours (rather than just time "at work") reveals that most people have 4–6 hours of truly productive work per day.
The four-day workweek (32 hours) is gaining traction. Pilot programs in Iceland, Japan, and the United Kingdom found similar or improved productivity with 20% fewer hours, alongside improved employee wellbeing and reduced burnout. The coming decades may see the standard workweek shrink just as it did in the 20th century.
Time Tracking for Freelancers and Self-Employed Workers
For freelancers and consultants, precise time tracking is the foundation of accurate billing and business profitability analysis. Best practices include:
- Log in real time rather than reconstructing from memory at the end of the day. Studies show recall-based time logs are typically 20–30% inaccurate.
- Round to consistent increments — most billing uses 6-minute increments (0.1 hour), 15-minute increments (0.25 hour), or 30-minute increments depending on your industry and rate.
- Categorize time by project and task type to identify which work is profitable and which is being under-billed.
- Track non-billable time too — administrative work, prospecting, and professional development. This reveals your true effective hourly rate and helps set accurate prices.
- Review weekly to catch missed entries and identify patterns in how you spend time.