Free Tool
Free Time Card Calculator
A time card calculator turns the hours and minutes on a time card into the decimal hours payroll systems expect, adds up the week, and splits regular from overtime hours. The conversion is one step: divide the minutes by 60. So 4 hours 30 minutes is 4.5 hours — not 4.30. Thirty minutes is half an hour, so it becomes .50 in decimal time; 15 minutes is .25 and 45 minutes is .75. Entering “4.30” instead of “4.50” shorts the employee 12 minutes. It works as a time clock converter and timesheet converter in one — no lookup chart required. Use the calculator below to convert a single entry, total a full week, and see how many hours cross into overtime.
Time card calculator
Time clock converter: one entry to decimal hours
Type the hours and minutes from a time card. The minutes are divided by 60 — that is the entire conversion.
4:30 = 4.50 hours · 30 ÷ 60 = 0.50
Total a week and split overtime
Enter each day as clock-in and clock-out times, or switch to hours worked and type totals like 8:45 or 8.75.
| Day | Clock in | Clock out | Unpaid break (min) | Hours:minutes | Decimal |
|---|---|---|---|---|---|
| Monday | 8:00 | 8.00 | |||
| Tuesday | 8:45 | 8.75 | |||
| Wednesday | 8:45 | 8.75 | |||
| Thursday | 9:30 | 9.50 | |||
| Friday | 9:00 | 9.00 | |||
| Saturday | 3:40 | 3.67 | |||
| Sunday | — | — | |||
| Weekly total | 47:40 | 47.67 | |||
Overtime defaults to 40 hours because that is the federal Fair Labor Standards Act threshold: in most cases the pay premium is time and a half for hours over 40 in a workweek, though state rules and union agreements can vary. Change the threshold above to match your own policy, and see California break and overtime compliance if you run crews in California.
Minutes to Decimal Hours Conversion Chart
The values payroll admins look up most often. Every one of them is just the minutes divided by 60, rounded to two decimal places.
| Minutes | Decimal hours | Example entry | Decimal entry |
|---|---|---|---|
| 5 minutes | 0.08 | 8:05 | 8.08 |
| 10 minutes | 0.17 | 8:10 | 8.17 |
| 15 minutes | 0.25 | 8:15 | 8.25 |
| 20 minutes | 0.33 | 8:20 | 8.33 |
| 30 minutes | 0.50 | 8:30 | 8.50 |
| 40 minutes | 0.67 | 8:40 | 8.67 |
| 45 minutes | 0.75 | 8:45 | 8.75 |
| 50 minutes | 0.83 | 8:50 | 8.83 |
| 60 minutes | 1.00 | 9:00 | 9.00 |
Need the whole chart, plus what manual conversion costs a service business every week? Read how to convert time clock hours and minutes to decimals.
How to Calculate a Time Card by Hand
1. Total each day in hours and minutes
Subtract the clock-in time from the clock-out time, then subtract any unpaid break. A 7:00 a.m. to 3:30 p.m. shift with a 30-minute lunch is 8 hours 0 minutes. If a shift crosses midnight, count the minutes to midnight and add the minutes after it.
2. Round the punches before you convert — consistently
If your policy rounds to the quarter hour, apply the 7-minute rule to clock-ins and clock-outs alike, in the same increment, every day. Rounding that only ever favors the employer is a wage problem, not a math shortcut.
3. Convert the minutes to decimal hours
Divide the minutes by 60 and keep two decimal places: 8 hours 45 minutes is 8.75, 8 hours 30 minutes is 8.50, 8 hours 10 minutes is 8.17. Convert each day, then add the decimals — or add the minutes and convert once, which is what the calculator above does to avoid stacking rounding errors.
4. Split regular hours from overtime
Compare the weekly total to your overtime threshold — 40 hours in a workweek under the federal FLSA. Hours up to the threshold are regular; everything above it is overtime, paid at your overtime rate. Do this per workweek, not per pay period: a biweekly check covers two separate 40-hour workweeks.
Frequently Asked Questions
How do you convert minutes to decimal hours?
Divide the minutes by 60 and round to two places. 15 minutes is .25, 30 minutes is .50, and 45 minutes is .75; minutes that do not divide evenly round, so 10 minutes is .17 and 50 minutes is .83. The hours never change — only the minutes are converted. Our guide on converting time clock hours and minutes to decimals walks through the same math with a full conversion chart.
Why is 4:30 on a time card 4.5 hours and not 4.30?
Because a time card reads in minutes and payroll reads in hundredths of an hour. Thirty minutes is half an hour, so 4:30 becomes 4.50 in decimal time. Typing “4.30” instead pays .30 of an hour — 18 minutes — and shorts the employee 12 minutes. It is the single most common manual-entry mistake, and it repeats on every card until someone notices.
What is the 7-minute rule for rounding time cards?
It is the Department of Labor’s guideline for rounding punches to the nearest quarter hour: minutes 1 through 7 past the mark may round down, and minutes 8 through 14 must round up to the quarter hour. Rounding has to be applied the same way to clock-ins and clock-outs so it never consistently favors the employer under the FLSA, and you cannot round in increments greater than 15 minutes. See rounding time sheets using the 7-minute rule for the full rules. Round the punches first, then convert the rounded totals to decimals.
When does overtime start?
Under the federal Fair Labor Standards Act, nonexempt employees earn overtime for hours worked over 40 in a workweek — in most cases time and a half, though state rules and union agreements can vary. That is why this calculator defaults to a 40-hour weekly threshold and lets you change it. California has its own daily and weekly rules; see California compliance for how Chronotek Pro handles those workflows.
Does the calculator handle overnight shifts and unpaid breaks?
Yes. If the clock-out time is earlier than the clock-in time, the shift is treated as crossing midnight — a 22:00 to 06:00 shift counts as 8 hours. Unpaid break minutes are subtracted from that day before the decimal conversion, so a 7:00 to 15:30 shift with a 30-minute unpaid lunch totals 8.00 hours instead of 8.50.
Do I still need a time clock if I have a calculator?
A calculator fixes the math, not the numbers going into it — a padded or guessed-at punch time converts to a perfectly precise wrong answer. Chronotek Pro’s timekeeping captures GPS-verified clock-ins from the job site and produces payroll-ready decimal hours and overtime totals automatically, with no conversion step at all. See pricing for what that costs.
How do you write 45 minutes on a timesheet?
On a decimal timesheet, 45 minutes is .75 of an hour — so 3 hours 45 minutes is written 3.75, and 45 minutes alone is 0.75. If the timesheet records hours and minutes instead, write 3:45 and convert before payroll. The same quarter-hour values cover most entries: 15 minutes is .25, 30 minutes is .50, and 45 minutes is .75. Type the entry into the converter above and it does the division for you.
Can I use this as a timesheet converter for payroll?
Yes. The single-entry box works as a time clock converter — it turns any hours-and-minutes value into the decimal hours payroll software expects — and the weekly time card converts a full week of punches into payroll-ready totals with regular and overtime hours split out. It replaces the manual lookup a conversion chart requires, though the printable chart is handy for posting next to a time clock.
Let the time clock do the math
Chronotek Pro records GPS-verified clock-ins from the job site and turns them into payroll-ready decimal hours and overtime totals — no chart, no calculator, no 12-minute typos. Start a 30-day free trial, no credit card required.
Related reading: Convert time clock hours and minutes to decimals · Rounding time sheets using the 7-minute rule · Chronotek Pro pricing