Hours Worked and Average Employees Calculator for the OSHA 300A

Besides the case totals, the Form 300A summary wants two figures about your workforce. Paragraph (b)(2)(ii) of 29 CFR 1904.32 lists them among the things you enter: the "annual average number of employees covered by the OSHA 300 Log, and the total hours worked by all employees covered by the OSHA 300 Log".

OSHA's forms package includes a worksheet for both, and this calculator follows its steps. For the average, enter the employees paid in each pay period added together for the year, and how many pay periods there were. For the hours, choose whether they come from your payroll or time records or from OSHA's optional estimate, then fill in the matching boxes. Your inputs are written into the page address as you type, so a copied link reopens your own numbers.

Worked example: Acme's 26 pay periods

This one is the worksheet's own. Acme Construction counted how many employees it paid in each of its 26 pay periods: 10 in the first, 0 in the second, then 15, 30, 40, and on through 20 and 15 to 10 in the last. Those 26 counts add up to 830. That's a sum of counts, not a claim that Acme had 830 people on staff.

Dividing gives 830 ÷ 26 = 31.92. The worksheet's next step says "Round the answer to the next highest whole number." So Acme writes 32 in the average-employees box of its summary. The calculator opens on these figures and shows the same two numbers.

Acme's example stops at the headcount; the worksheet gives no hours for it. The calculator's default of 64,000 hours from payroll is a figure made up for this page. With it, the hours come to 32.0 full-time equivalents at 2,000 hours each.

Worked example: estimating hours with OSHA's worksheet

Another made-up example. Say a business can't pull hours worked out of its records. Set Where total hours worked come from to OSHA's optional estimate worksheet. The worksheet introduces itself this way: "If this number isn’t available, you can use this optional worksheet to estimate it."

• Full-time hours: 25 full-time employees at 2,000 hours a year each come to 50,000 hours.
• Add 1,500 overtime hours.
• Add 9,250.5 hours worked by part-time and seasonal staff.

The total is 60,750.50 hours. Like the average, the estimate is rounded up to a whole number, so the summary gets 60,751. Divided by 2,000, that's 30.4 full-time equivalents. The average of 32 doesn't change, because it comes from the pay-period counts, not from the hours.

Counting employees

The average starts with a count for every pay period in the year. The worksheet's first step reads: "Add up and then enter the number of employees your establishment paid IN EACH PAY PERIOD during the year. Be sure to include all employees: full-time, part-time, temporary, seasonal, salaried, and hourly." Its second step has you count the pay periods, and a pay period in which you paid nobody still counts: it adds 0 to the total and 1 to the divisor.

There's no shortcut through tax forms. In the worksheet's words: "You CANNOT divide the total number of W2s by the number of pay periods to calculate average employment." The count has to be built up one pay period at a time, which is what the first box of the calculator asks for.

When the headcount barely changes, the worksheet lets you use the steady number itself as the average. The formula matters when it swings with the seasons or as the business grows or shrinks. It also asks you to sanity-check the answer: is it close to the number working on a typical day, and does it sit between your smallest and largest pay-period counts?

Rounding up bites when the average is just over a whole number. Say a weekly payroll's counts add up to 5,203 across 52 pay periods: the calculator shows 100.06 before rounding, and 101 as the average.

What counts as hours worked

The worksheet is plain about what goes in: "Include hours worked by salaried, hourly, part-time, and seasonal workers, as well as hours worked by other workers subject to day-to-day supervision by your establishment..." And about what stays out: "Do not include vacation, sick leave, holidays, or any other non-work time, even if employees were paid for it."

Payroll that tracks only paid hours, or salaried staff with no hourly record, need an estimate of the time people were actually on the job. The worksheet asks for that estimate in those cases, rather than the paid figure. The table below the calculator sets out what to count and what to leave out.

How these numbers are used

The hours total is the denominator of every injury rate. Put it into the TRIR calculator with your case counts to get the TRIR, DART rate and days-away rate.

The average number of employees is a different thing from the headcounts OSHA's size rules use:

• For the partial exemption for size, 29 CFR 1904.1 looks at the whole company, not one establishment, and says "you need to determine your company's peak employment during the last calendar year". Who has to keep OSHA injury records covers that test, and the industry exemption alongside it, in full.
• For electronic submission, 29 CFR 1904.41 counts people. Under its paragraph (b)(2), "each individual employed in the establishment at any time during the calendar year counts as one employee".

So a seasonal business can show an average of 32 on its 300A and still have had many more people on its books at some point in the year. Check each rule against its own count.

Rounding

Both figures on the 300A are whole numbers, and the calculator rounds each one up. A quotient that's already whole, such as 780 ÷ 26 = 30, is left alone.

The estimate is added up to the hundredth of an hour first and rounded once at the end. So 1,000.1 hours plus 999.9 hours is exactly 2,000, not 2,001. The calculator shows the unrounded estimate beside the rounded total so you can see the step.

Full-time equivalents are the hours divided by 2,000, shown to one decimal and rounded half up. They aren't one of the two figures the worksheet produces; they're here to show the hours on the same 2,000-hour base the rate pages use.

Sources (4)

1. OSHA, Forms for Recording Work-Related Injuries and Illnesses (Worksheet to Help You Fill Out the Summary) osha.gov
2. 29 CFR 1904.32, Annual summary (eCFR) ecfr.gov
3. 29 CFR 1904.1, Partial exemption for employers with 10 or fewer employees (eCFR) ecfr.gov
4. 29 CFR 1904.41, Electronic submission of injury and illness records to OSHA (eCFR) ecfr.gov

Updated September 19, 2026