Determine your regular rate of pay first
Non-exempt employees working more than 40 hours during a fixed seven-day workweek must receive at least 1.5 times their regular rate of pay for every extra hour. Calculating what you are owed requires finding your true regular rate, not just your base hourly rate.
If you earn an hourly wage with no shift differentials or bonuses, the math is straightforward. An hourly rate of $20.00 yields an overtime rate of $30.00 per hour ($20.00 x 1.5). When an employer pays you straight time for 10 overtime hours, they owe you the remaining half-time premium of $10.00 per hour, or $100.00. If they recorded those 10 hours and paid zero dollars, they owe you the full $30.00 per hour, or $300.00.
If you receive nondiscretionary bonuses, commissions, or shift differentials, those earnings must be rolled into your weekly earnings before calculating your regular rate. To find the regular rate in any given week, divide your total compensation for the workweek by the total hours worked that week. Multiply that resulting regular rate by 0.5 to find your additional overtime premium per hour, or by 1.5 if the hours went completely unpaid.
Your employer cannot average your hours across two weeks to avoid overtime. Working 50 hours in the first week of a biweekly pay period and 30 hours in the second week equals 10 hours of overtime in week one. Pay periods do not define overtime thresholds; a set seven-day workweek does.
Gather work records and reconstruct missing time cards
Employers carry the legal burden under federal and state wage laws to track employee hours accurately. When time records are missing, altered, or unrecorded because of off-the-clock work, courts and wage agencies accept reasonable employee estimates.
Collect every piece of documentation before speaking to payroll. Store these items on a personal device or personal cloud storage, never on a company computer:
- Itemized pay stubs showing gross pay, hourly rates, and recorded hours.
- Timesheets, electronic punch records, and timecard modification logs.
- Building badge access logs and parking garage timestamps.
- Sent emails, internal messaging timestamps, and dispatch logs showing work activity outside scheduled shifts.
- Personal calendars, notes, or GPS location records confirming shift start and end times.
Build a spreadsheet listing each workweek row by row. Record the start date of the workweek, days worked, daily hours, total weekly hours, hours worked above 40, wages actually received, and the unpaid overtime balance.
Draft a factual computation for payroll
Keep all initial written requests focused strictly on dates, times, and arithmetic. An overtime demand is an audit of hours worked against compensation paid, not an airing of workplace grievances.
What to include in your written computation:
- Your exact job title, employment dates, and designated workweek schedule.
- The pay periods where overtime hours were omitted or underpaid.
- Your regular hourly rate of pay and how it was calculated.
- The exact number of unpaid overtime hours per week.
- The total gross balance owed.
- A firm date for payment, such as ten business days from receipt.
What to leave out:
- Allegations of personal hostility, favoritism, or bad management.
- Threats of police reports or criminal theft charges.
- Speculative or estimated numbers when exact time stamps exist.
- Conversations about unrelated workplace disputes or job evaluations.
State laws change how overtime and penalties add up
While federal rules provide the baseline 40-hour weekly overtime requirement, the rules in every state introduce distinct thresholds, salary calculation methods, and statutory penalties.
In California, daily overtime rules apply alongside weekly thresholds under Cal. Lab. Code § 510. Work beyond 8 hours in a single workday requires 1.5 times the regular rate. Work beyond 12 hours in a workday requires double time (2 times the regular rate). Working seven consecutive days in a workweek triggers time-and-a-half for the first 8 hours on the seventh day and double time for all hours worked past 8. When an employer willfully withholds wages upon separation, Cal. Lab. Code § 203(a) establishes a waiting time penalty: your daily wage continues to accrue as a penalty for each calendar day the wages remain unpaid, up to 30 days. You have 3 years to file an overtime claim with the California Labor Commissioner's Office. Review the statutory breakdown on the California unpaid wage page.
In Illinois, overtime is set at 1.5 times the regular rate for hours worked beyond 40 per workweek under 820 ILCS 105/4a, with no daily overtime trigger. However, Illinois statutory damages are severe. Under 820 ILCS 105/12(a), an employee filing a civil action can recover treble damages—three times the amount of the underpayment—plus damages of 5% of the underpayment for every month it remains unpaid, along with reasonable attorney's fees. To file an administrative claim without going to court, you must submit your complaint to the Fair Labor Standards Division within 1 year after the compensation became due under 820 ILCS 115/11. Full details are available on the Illinois unpaid wage page.
In Pennsylvania, 43 P.S. § 333.104(c) requires 1.5 times the regular rate for weekly hours over 40. Pennsylvania law provides a unique calculation rule for salaried non-exempt workers: under 34 Pa. Code § 231.43(g), your regular rate is calculated by dividing your salary by 40 hours, rather than using fluctuating workweek formulas. Under the Wage Payment and Collection Law, 43 P.S. § 260.10, if overtime remains unpaid for 30 days past your regular payday and the employer cannot demonstrate a good-faith contest, you may claim liquidated damages equal to 25% of the unpaid balance or $500, whichever is greater. State claims carry a 3-year statute of limitations under 43 P.S. § 260.9a(g) and can be submitted to the Pennsylvania Department of Labor & Industry Bureau of Labor Law Compliance. See additional rules on the Pennsylvania unpaid wage page.
Escalate with a formal certified demand letter
When internal emails to payroll yield delays, evasions, or denials, verbal conversations must stop. Sending a formal demand letter by USPS Certified Mail with Return Receipt changes the administrative standing of your dispute.
A certified letter produces a verifiable paper trail that confirms the employer received your mathematical breakdown on a specific date. The physical green card signed by company personnel prevents management from claiming in a later wage claim or court filing that they were never informed of the specific hours in question.
Address the letter directly to the business owner, registered agent, or payroll director. Include your itemized spreadsheet, specify the governing state statutes and statutory penalties, and provide a clear deadline for payment before you file an administrative claim or lawsuit.
When a demand letter is the wrong tool
A demand letter is not appropriate for every wage dispute. Using this approach under the wrong circumstances can waste time or jeopardize your recovery.
If your employer has filed for Chapter 7 or Chapter 11 bankruptcy, federal law imposes an automatic stay that halts all private wage collection efforts and demands. You must instead file a Proof of Claim directly with the federal bankruptcy court handling the case.
If your claims fall outside the statutory filing deadlines—such as exceeding the 1-year administrative window under Illinois law or the 3-year limitations periods in California and Pennsylvania—a demand letter cannot resurrect expired statutory penalties.
If your position is legitimately classified as exempt under executive, administrative, or professional criteria and paid an eligible salary, you are not legally entitled to overtime premiums regardless of hours worked. Union members subject to a collective bargaining agreement requiring mandatory grievance and arbitration procedures must also follow their contract's dispute process rather than pursuing individual wage demands.