Small business owners manage hundreds of details to operate their businesses every day. What's more, many of the daily tasks of running a business involve math skills. From totaling receipts and making deposits to paying bills and doing bookkeeping, math is everywhere in running a business. And that's especially true when it comes to calculating time cards. Converting minutes to decimals and subtracting start times from end times can be a confusing process, but fortunately the steps for calculating pay time cards can be easily followed when each is carefully carried out.
Convert any "p.m." times, such as 2:30 p.m., into standard 24-hour time by adding 12 to the number of hours listed. For example, change 2:30 p.m. to 14:30 and 6 p.m. to 18:00. "A.m." times generally should not be changed.
Convert the minutes recorded for each time into decimals by dividing the number of minutes listed by 60. For example, 15 minutes divided by 60 minutes is 0.25 (15/60 = 0.25), indicating that 15 minutes is one quarter (0.25) of an hour. Or again, 35 minutes divided by 60 minutes equals 0.58 of an hour (35/60 = 0.58).
Subtract the ending time from the starting time for each time entry on the card. For example, if a worker started work at 9:15 a.m. and ended at 5 p.m., you'd convert 9:15 a.m. to 9.25 (15/ 60 = 0.25) and 5 p.m. to 17.00 (adding 12 for p.m. times). Then subtract 9.25 from 17.00 to discover that this employee has worked 7.75 hours (17.00 - 9.25 = 7.75).
Calculate overnight working hours in two steps: First, calculate from the starting time to midnight (12 a.m.), and then re-start the calculation from midnight (0:00 hours on the next day) to the end of the shift. For example, an employee working from 11 p.m. to 7 a.m. the next day actually worked from 11 p.m. to midnight (24.0 - 23.0 = 1.0 hours), and then worked from midnight on the new day (0:00 hours) to 7 a.m. (7.0 - 0.0 = 7.0 hours), for a total of 8.0 hours worked.
Add each of the individual work-day calculations together to determine the total number of hours worked on the time card. For example, if the employee worked 8.0 hours on Monday, 7.5 hours on Tuesday, 8.25 hours on Wednesday, 8.0 hours on Thursday and 7.75 hours on Friday, his total would be 39.5 hours worked for the week (8.0 + 7.5 + 8.25 + 8.0 + 7.75 = 39.5).
Mike Andrews is a freelance writer and serial entrepreneur focused on small-business and entrepreneurship for average people. He holds a bachelor's degree in biblical studies and a master's degree in theology and has appeared in a wide array of print and online periodicals including "HiCall," "Mature Living" and "Caregivers Home Companion."