How to Calculate Average Weekly Wage in Illinois Workers’ Comp

By Workers’ Compensation Attorney Matthew C. Jones | Updated October 14, 2026

In Illinois workers’ compensation, average weekly wage (AWW) is generally calculated from your actual gross earnings during the 52-week period ending with your last full pay period before the injury. The calculation can change when you lost time from work, started the job less than a year earlier, worked qualifying additional hours, or had a second job your employer knew about.

Your AWW helps determine your temporary total disability checks and the weekly rate used in many permanent-disability calculations. If the insurance company leaves out qualifying earnings or divides by too many weeks, you may receive less than you are owed while off work and less in a later settlement.

How Is Average Weekly Wage Calculated Under Illinois Law?

Section 10 of the Illinois Workers’ Compensation Act, 820 ILCS 305/10, establishes the calculation rules. The Illinois Workers’ Compensation Commission’s handbook also explains that AWW is generally based on gross, pre-tax wages and that the employee’s circumstances can change the calculation.

1. The usual 52-week calculation

The starting method uses actual earnings in the employment where you were working when injured, during the 52 weeks ending with the last day of your last full pay period before the injury. The statute generally excludes overtime and bonuses, subject to the legal distinctions discussed below.

Example: A year-round employee has $62,400 in counted earnings over the applicable 52 weeks. With no adjustment to the divisor, the AWW is $62,400 ÷ 52 = $1,200.

Use the correct payroll period. A calendar-year W-2 may be useful, but it may not cover the same dates as the statutory wage period.

2. The lost-time adjustment: five or more calendar days

If the employee lost five or more calendar days during that period, whether or not in the same week, Section 10 provides for deducting the time lost and dividing the remaining earnings by the remaining weeks and parts of weeks.

Example: Assume the records establish $42,000 in counted earnings and ten full weeks of qualifying unpaid lost time, leaving a 42-week divisor. The AWW would be $42,000 ÷ 42 = $1,000. Dividing the same earnings by 52 would produce approximately $807.69.

The reason for the absence, pay received, work schedule, and employment arrangement must be checked. A vacation, paid holiday, regular day off, or gap between assignments does not automatically justify the same adjustment. Partial weeks also require attention; the statute refers to weeks and parts of weeks.

3. Employment lasting less than 52 weeks

When the employment lasted less than 52 weeks before the injury, Section 10 calls for dividing earnings during that employment by the weeks and parts of weeks during which the employee actually earned wages.

Example: An employee has $12,000 in counted earnings during ten applicable weeks before being injured. Using a ten-week divisor produces an AWW of $1,200. The wages should not simply be spread over a year in which the employee did not hold that job.

Keep the hiring date, first pay period, payroll records, and schedules. They are especially important for new hires and staffing-agency and temporary employees.

4. Comparable-employee earnings when the ordinary methods are impractical

If very short employment or the casual nature or terms of the employment make the other methods impractical, Section 10 directs attention to what a person in the same grade, doing the same work for the same employer and the same weekly hours, earned or would have earned during the preceding 52 weeks.

This can matter when someone is injured shortly after starting a job. The wage evidence may need to include a comparable employee’s records and the hours the new employee was hired to work.

Does Overtime Count in Average Weekly Wage?

Sometimes. Section 10 generally excludes overtime, but Illinois courts distinguish voluntary extra hours from hours that are part of the employee’s regular employment. Relevant questions include whether the additional hours were required as a condition of employment or were a set number consistently worked each week.

A payroll label does not resolve that issue. Evidence may include schedules, union contracts, time records, supervisor instructions, and what happened if the worker tried to leave after the regular shift. Qualifying additional hours are generally evaluated at the regular hourly rate, rather than automatically adding the time-and-a-half premium.

Example: Suppose a worker earns $25 per hour and the evidence supports a regular, required 48-hour week. Counting those hours at straight time would produce $1,200 per week, compared with $1,000 for a 40-hour week. Whether the extra eight hours qualify must be established.

Our dedicated article explains the cases and evidence in more detail: Does overtime count in an Illinois workers’ comp average weekly wage? The appellate decision in Airborne Express, Inc. v. Illinois Workers’ Compensation Commission illustrates why regularly working extra hours does not, by itself, settle the question.

What about bonuses, commissions, and other payroll items?

Section 10 generally excludes bonuses. Other compensation requires classification under the governing law and the employment terms. Separate ordinary wages, commissions, shift pay, contractual incentive payments, discretionary bonuses, and expense reimbursements in the payroll review. An item’s label alone may not explain what the payment actually represents.

If your hourly rate changed during the wage period, check the actual earnings at the applicable rates. A recent raise does not automatically mean every earlier hour should be recalculated at the new rate.

Can Wages From a Second Job Count?

Yes, potentially. Section 10 provides that wages from concurrent employers are considered when the employer responsible for the claim knew about the other employment before the injury.

For example, a nurse who also worked another nursing job may need payroll records from both employers and proof that the employer responsible for the claim knew about the second job. Scheduling messages, discussions with a supervisor, or employment paperwork may help establish that knowledge.

Having a second job before the injury is a different issue from starting or continuing work while receiving benefits. For that question, read whether you can work while on workers’ comp.

Part-time, seasonal, and construction work

A part-time worker’s wage is not automatically converted into a full-time, 40-hour wage. Seasonal and construction work also require a careful review of the actual employment period and lost time. The appropriate Section 10 method depends on the facts; an annual income total alone may leave important questions unanswered.

Teachers paid over 12 months for a shorter school calendar

A teacher’s paycheck schedule and the period over which the salary was earned may be different. A school-year salary paid in twelve-month installments requires review of the contract, calendar, actual earnings, and applicable calculation method.

Coaching stipends, summer school, additional assignments, and qualifying concurrent employment may require separate attention. There is no universal divisor that fits every teacher. Our guide to Illinois workers’ compensation for teachers and school employees discusses these issues alongside school injuries and work restrictions.

How Does Average Weekly Wage Affect Workers’ Comp Checks and Settlements?

For qualifying temporary total disability, or TTD, the usual starting rate is 66⅔% of AWW. Many scheduled and person-as-a-whole permanent partial disability, or PPD, calculations use a weekly rate based on 60% of AWW. Statutory minimums and maximums can change the amount payable.

In that example, correcting the AWW increases TTD by approximately $133.33 per compensable week. Over 60 compensable weeks, that is approximately $8,000 in additional TTD. It also increases the illustrated 100-week PPD calculation by $12,000. These examples assume no statutory minimum or maximum changes the rates; the actual number of compensable weeks and the proper permanent-disability category must be established in the claim.

Where AWW fits into the Illinois settlement chart

For a scheduled PPD calculation, the basic math combines the body part’s statutory weeks, the supported percentage of loss, and the applicable PPD weekly rate. AWW helps determine that weekly rate.

For example, 20% of a 500-week person-as-a-whole measure equals 100 weeks. Which benefit category and percentage apply must be evaluated separately. The Illinois workers’ comp settlement chart explains the statutory schedule and why it cannot determine the complete value of every claim.

Permanent restrictions may also raise loss-of-trade, wage differential, or permanent total disability issues. Those benefit categories require their own analysis. In a published firm result, a truck driver whose hand and thumb injury prevented a return to commercial driving received a $475,000 wage differential settlement. See our Illinois workers’ compensation case results. That result illustrates the importance of evaluating earning loss; it is not an AWW-only calculation or a prediction of another recovery.

Your AWW and the statewide average weekly wage are different

Your individual AWW comes from your employment and wage evidence. The statewide average weekly wage (SAWW) is a separate figure used to establish certain benefit limits. Do not substitute the statewide figure for your own payroll calculation.

Use the IWCC’s official benefit-rate tables for the applicable injury-date period and benefit category. Our guide to how much Illinois workers’ comp pays explains TTD, TPD, maintenance, and other benefits.

Light duty and TPD require a separate earnings comparison

When light duty pays less while you are recovering, temporary partial disability (TPD) may be due. For injuries on or after June 28, 2011, the starting calculation is two-thirds of the difference between the average amount you would be able to earn in your pre-injury job or jobs and your gross earnings in the light-duty job, subject to the applicable limits. A raise in the former job may matter to that comparison. TPD is not simply two-thirds of the original AWW.

Reduced hours and lost overtime can matter even when the hourly rate stays the same. Read our Illinois light-duty guide and the TPD section of the benefits/pay guide.

What Should You Do If the Insurance Company Used the Wrong AWW?

1. Request the calculation in writing. Ask for the wage period, earnings included, exclusions, divisor, AWW, and benefit rate.
2. Collect the underlying records. Get pay stubs and a detailed payroll history showing hours, rates, earnings categories, and dates worked.
3. Identify gaps and employment changes. Mark qualifying lost time, the hiring date, rate changes, and partial weeks.
4. Document special wage issues. Preserve required schedules, union terms, incentive agreements, and evidence of known concurrent employment.
5. Compare the corrected rate with the payments. Review the compensable periods and amounts actually paid. Missing checks and an understated rate are different problems.
6. Address the issue before settling. Request any supported correction and unpaid benefits. If the parties disagree, the wage issue may need evidence and a determination before the IWCC.

When I review a wage calculation, I look at both sides of the formula: the earnings being counted and the weeks being used to divide them. A wage summary is most useful when it can be checked against the source records. A W-2 or one recent paycheck may not show the correct wage period, lost time, excluded payments, or your actual schedule.

If checks have stopped altogether, read what to do when workers’ comp stops your checks. For the discussion that may precede a contested benefits hearing, see our guide to Illinois workers’ comp pretrial conferences.

Frequently Asked Questions About Illinois Average Weekly Wage

Is AWW based on gross pay or take-home pay?

Generally, gross earnings before taxes and payroll deductions. The earnings still have to be classified under Section 10; not every payment on a paycheck necessarily counts.

Is average weekly wage always annual income divided by 52?

No. Qualifying lost time, employment lasting less than a year, or circumstances requiring comparable-employee evidence can change the calculation.

Do unpaid weeks lower my workers’ comp rate?

They may create a divisor issue rather than simply lower the rate. Section 10 addresses five or more calendar days of lost time. The actual absence, employment terms, and payroll evidence must be reviewed.

Does overtime count?

It may when the hours qualify as part of the employee’s regular employment under Illinois case law. Voluntary extra hours and overtime premiums are not automatically included. See our detailed overtime and AWW article.

Can my second job count?

Potentially, when it was concurrent employment and the employer responsible for the claim knew about it before the injury. Payroll records and proof of that knowledge are important.

How does AWW affect my settlement?

AWW helps determine the weekly rate used in many PPD calculations. An understated rate can reduce the calculation even if the parties agree on the same disability percentage. Benefit limits and the proper disability category also matter.

Can an incorrect wage rate be corrected after checks have started?

Yes. Starting payments does not automatically establish that the calculation is correct. Supporting wage records may justify a correction and a request for unpaid differences. Address the issue before signing a settlement, because approved settlement terms and the procedural status of the case can affect your options.

About the Author

Matthew C. Jones is a partner at McHargue & Jones, LLC and has represented Illinois injured workers since 2006. His practice includes disputed benefits, denied treatment, permanent work restrictions, and settlement claims. He has tried more than 100 workers’ compensation cases before the Illinois Workers’ Compensation Commission.

Illinois Legal Sources

• 820 ILCS 305/10 — average weekly wage.
• 820 ILCS 305/8 — disability and other benefits.
• IWCC handbook — wage calculations, temporary disability, and permanent disability.
• IWCC current and historical benefit rates.
• Airborne Express, Inc. v. Illinois Workers’ Compensation Commission, 372 Ill. App. 3d 549 (2007) — overtime and regular working hours.

This article provides general information about Illinois law. The correct wage calculation depends on the records and facts of the claim. Past case results do not guarantee a future result.