My Timesheet Said 40.60 Hours. My Real Hours Were 41.67 — and the Gap Cost Me $35
I added up my timesheet the way anyone would: 7.45, 8.20, 7.50, 8.10, 9.35. The total came to 40.60 hours, so I figured I'd barely scraped into overtime. The number my payroll portal showed was different, and my paycheck was $35 higher than my own maths predicted. It took me a good ten minutes to realise the mistake was mine, not theirs: I had been adding hours and minutes as if they were decimals.
This post is for hourly workers, freelancers who bill by the hour, and anyone who fills in a weekly timesheet by hand. By the end you'll know how to turn clock times into decimal hours correctly, how overtime magnifies a small conversion slip, and how to check your own time card in under a minute.
⚠️ Disclaimer
This article is for informational purposes only and does not constitute legal or financial advice. Overtime rules vary by country, state and employer. Always check your contract or consult a qualified professional for your specific situation.
Why Is 7:45 Not the Same as 7.45 Hours?
Decimal hours express a duration as a single base-10 number, where the part after the point is a fraction of an hour. Clock time is base-60: an hour holds 60 minutes, so 45 minutes is 0.75 of an hour, not 0.45.
That's the whole trap. Clocks count in sixties, calculators count in tens. When you type "7.45" into a spreadsheet, it means seven and forty-five hundredths of an hour, which is only 27 minutes. Every entry you write as hours-dot-minutes is quietly understated, and the error grows the more minutes you work.
The U.S. Department of Labor's Fair Labor Standards Act (FLSA) requires covered non-exempt employees to receive at least 1.5 times their regular rate for hours worked beyond 40 in a workweek. That's where a small slip stops being an annoyance and starts costing real money: the difference lands in your overtime hours, which pay the most.
How Do You Convert Minutes to Decimal Hours?
The conversion is one division. Divide the minutes by 60, then add the whole hours.
So 7 hours 45 minutes is 7 + (45 ÷ 60) = 7.75. Here are the conversions I keep taped inside my locker:
| Minutes | Decimal hour | Quick check |
|---|---|---|
| 6 | 0.10 | One tenth |
| 15 | 0.25 | A quarter |
| 20 | 0.33 | A third |
| 30 | 0.50 | Half |
| 45 | 0.75 | Three quarters |
| 50 | 0.83 | Five sixths |
💡 Pro Tip
Don't want to do the division every day? Paste any hours-and-minutes value into the Time to Decimal converter and copy the result straight into your payroll form.
The Week That Cost Me $35
Here is the exact week. I earn $22 an hour, with overtime at 1.5× after 40 hours, which is the FLSA default.
| Day | Worked (h:mm) | Typed as | Correct decimal |
|---|---|---|---|
| Mon | 7:45 | 7.45 | 7.75 |
| Tue | 8:20 | 8.20 | 8.33 |
| Wed | 7:50 | 7.50 | 7.83 |
| Thu | 8:10 | 8.10 | 8.17 |
| Fri | 9:35 | 9.35 | 9.58 |
The wrong way: 7.45 + 8.20 + 7.50 + 8.10 + 9.35 = 40.60 hours. That gives 40 regular hours plus 0.60 overtime hours.
The right way: add the minutes first. 465 + 500 + 470 + 490 + 575 = 2,500 minutes, and 2,500 ÷ 60 = 41.67 hours. That's 40 regular hours plus 1.67 overtime hours.
| Method | Regular pay | Overtime pay | Total |
|---|---|---|---|
| Wrong (40.60 h) | $880.00 | 0.60 × $33 = $19.80 | $899.80 |
| Right (41.67 h) | $880.00 | 1.67 × $33 = $55.00 | $935.00 |
That's $35.20 short in a single week, about $1,830 over a year if it happened every week. The gap is bigger than it looks because the missing 1.07 hours were all overtime hours, paid at $33 rather than $22.
Key Takeaway
Always add minutes together first and convert to decimals once at the end. Converting each day by eye, or typing h:mm as h.mm, is how small errors pile up.
The same slip hurts in other currencies too. At £15 an hour, losing 1.07 straight-time hours is £16.00; at A$32 an hour it's A$34.13. Add an overtime premium and the loss grows by half again.
What Is the 7-Minute Rule?
The 7-minute rule is a payroll rounding convention: punches are rounded to the nearest quarter hour, so minutes 1–7 round down and minutes 8–14 round up. The U.S. Department of Labor permits rounding under 29 CFR 785.48, provided that it averages out and doesn't consistently favour the employer.
Rounding is a separate issue from the decimal slip above, but they compound. If your employer rounds punches and you convert by hand, you can end up two steps from the truth.
| Punch | Exact | Nearest 15 min | Nearest 6 min |
|---|---|---|---|
| 9:07 | 9:07 | 9:00 | 9:06 |
| 9:08 | 9:08 | 9:15 | 9:09 |
| 5:22 | 5:22 | 5:15 | 5:24 |
If you suspect the rounding goes one way, track your exact punches for a month and compare. The Time Card Calculator lets you switch rounding on and off (5, 6 or 15 minutes) so you can see precisely what the policy costs or gains you across a week.
⚠️ Note
The 40-hour weekly threshold is a US federal default. Some states, such as California, also require overtime after 8 hours in a single day, and the UK, Australia and Canada each have their own rules. Check what applies to your job.
Frequently Asked Questions
How do I convert 7 hours 45 minutes to a decimal?
Divide the minutes by 60 and add the hours: 45 ÷ 60 = 0.75, so 7:45 is 7.75 hours.
Should I convert each day or the weekly total?
Add all the hours and minutes first, carry any 60 minutes into an hour, then convert once. Converting each day and rounding to two decimals can drift by a few minutes over a week.
Is it legal for my employer to round my time?
In the US, rounding to the nearest 5, 6 or 15 minutes is allowed under 29 CFR 785.48 if it is neutral over time. Rounding that always favours the employer can be a wage violation. Rules differ elsewhere.
Do unpaid breaks come off before or after converting?
Subtract them in minutes before converting. A 9:00 to 17:30 shift with a 30-minute unpaid break is 8 hours 0 minutes, or exactly 8.00 decimal hours.
What if my shift crosses midnight?
Add 24 hours to the end time when it falls before the start time. A 22:00 to 06:00 shift is 8 hours, not negative 16.
Try It Yourself
Clock time counts in sixties and pay counts in tens, so every hand-added timesheet is one slip away from a short paycheck. Check yours in under a minute with the Time Card Calculator, which handles breaks, overnight shifts, rounding and overtime for you.
Then follow the money through: the Overtime Pay Calculator shows what your extra hours are really worth, the Paycheck Calculator estimates what lands in your account after tax, and the Salary Calculator converts your hourly rate into an annual figure. For quick one-off conversions, use Time to Decimal.
