How this instrument works
Illinois does not lean on the federal government alone for its overtime rule. The Illinois Minimum Wage Law (820 ILCS 105) sets its own requirement — one and one-half times the regular rate for every hour worked past 40 in a single workweek — and that threshold happens to land on exactly the same number the federal Fair Labor Standards Act uses. States without a wage-hour statute of their own simply borrow the federal formula by default; Illinois wrote the same number into its own code, which changes who enforces it and how, even though the arithmetic matches.
The calculation runs in two bands. Hours up to 40 price at the plain hourly rate and land in Regular pay (up to 40 hrs); every hour past 40 prices at 1.5 times that rate and lands in Overtime pay (over 40 hrs, 1.5x). Illinois sets no separate daily trigger the way California does — a ten-hour shift generates nothing on its own as long as the week's total stays at or under 40 — so the only number that decides overtime is the week's cumulative hours, not any single day's length. The sheet then adds a step most weekly overtime tools skip: Projected annual pay at this weekly rate multiplies the week's total by 52, turning one pay stub into a full-year figure.
Payroll staff at Illinois employers, hourly workers sizing up a job offer quoted by the week, and anyone comparing a shift job against a salaried one reach for a calculation shaped like this. It prices one hourly rate against one week's hours and stops there — it does not fold a non-discretionary bonus into the regular rate the way federal law requires, does not check whether a role is genuinely non-exempt, and the annualized figure assumes that same week repeats fifty-two times, which real schedules with holidays, slow weeks and raises rarely do.
- Enter your straight-time pay in Hourly rate, $ — the rate before any overtime premium applies.
- Enter the total hours actually worked that week in Hours worked in the week.
- Read Regular pay (up to 40 hrs) for the straight-time portion, capped at 40 hours no matter how many you logged.
- Check Overtime pay (over 40 hrs, 1.5x) for the premium owed on whatever ran past 40, then Total weekly pay for the full week's wage.
- Look at Projected annual pay at this weekly rate to see what that same week would total if it repeated for a full year.
Worked example — 45 hours at $15 an hour
Set Hourly rate, $ to 15 — Illinois' own state minimum wage as of the most recent phase-in step — and Hours worked in the week to 45. Regular pay (up to 40 hrs) reads $600.00: the first 40 hours priced at the plain $15 rate. The 5 hours beyond 40 fall into Overtime pay (over 40 hrs, 1.5x), priced at $22.50 an hour, for $112.50.
Total weekly pay comes to $712.50, and Projected annual pay at this weekly rate multiplies that by 52 for $37,050.00. That annual figure is a projection, not a promise: it assumes the same 45-hour week repeats without a single slow week, unpaid holiday, or raise, which is why the sheet labels it 'projected' rather than treating it as a salary.
Questions
Does Illinois have its own overtime law, or does it just follow federal rules?
Illinois writes its own overtime rule into the Illinois Minimum Wage Law (820 ILCS 105), rather than relying on the federal Fair Labor Standards Act by default. The state figure — 1.5 times the regular rate past 40 hours in a workweek — matches the federal threshold exactly, so the math this calculator runs satisfies both laws at once. The state statute matters most for coverage and enforcement, including its own wage-claim process through the Illinois Department of Labor, not a different formula.
Does Illinois add a daily overtime trigger like California?
No. Illinois counts overtime only by the workweek, the same way the federal FLSA does — cross 40 hours in a week and the excess pays at 1.5x, however those hours were spread across the days. A state like California adds an 8-hour daily threshold on top of the weekly one; Illinois does not. A worker logging four 11-hour days and one 5-hour day (49 hours total) owes overtime only on the 9 hours past 40 for the week, nothing extra for any single long day.
What is the One Day Rest In Seven Act, and does it affect this calculation?
The One Day Rest In Seven Act (820 ILCS 140) is a separate Illinois law guaranteeing most employees 24 consecutive hours of rest in every seven-day period, plus a meal break on longer shifts. It governs scheduling, not pay rate, so it does not change how Regular pay or Overtime pay is calculated here. A week can be fully legal under this calculator's math and still violate the rest-day rule if an employer never scheduled the required day off — the two statutes are checked separately.
Are domestic workers, like nannies or home caregivers, covered by this overtime rule?
Generally yes, because of Illinois' own law. Federal rules exempt some categories of live-in or companionship-care domestic workers from overtime, but the Illinois Domestic Workers' Bill of Rights (2017) extended the state Minimum Wage Law's overtime protection to domestic workers regardless of that federal carve-out. A household employer in Illinois should generally apply the same 40-hour, 1.5x math this calculator runs, even for a role federal law alone would exempt.
Why does the projected annual figure matter if I only worked one week like this?
It turns a single week's pay into a comparable yearly number, useful for sizing up an hourly job against a salaried offer quoted annually. But it is only a projection: Projected annual pay at this weekly rate simply multiplies one week's total by 52, assuming every week matches this one exactly. Unpaid time off, holidays without pay, slower weeks with less overtime, and mid-year raises all pull the real annual total away from this straight-line estimate.
Does every hourly worker in Illinois qualify for the 1.5x rate?
No — only non-exempt employees. Executive, administrative, and professional staff meeting Illinois' salary and duties tests are exempt, largely mirroring the federal FLSA exemptions, along with certain outside-sales and specific agricultural roles. This calculator prices a non-exempt hourly worker's week; confirm exemption status against actual job duties before assuming the result applies to a particular paycheck.
References
Read this first: This instrument shows arithmetic, not advice. Real offers add fees, taxes and terms that vary by lender and place — verify the figures against your actual paperwork before deciding anything.