How Overtime Pay Is Calculated — Methodology & Regulatory Sources

1. Federal Overtime Calculation (FLSA Baseline)

Federal overtime compensation is governed by the Fair Labor Standards Act (FLSA), 29 U.S.C. § 207. Covered non-exempt employees must receive overtime pay for all hours worked in excess of 40 during a fixed, recurring 7-day workweek at a rate not less than one and one-half times (1.5×) their regular rate of pay.

A common payroll mistake is assuming the regular rate is always equal to the employee's base hourly wage. Under 29 CFR Part 778, the regular rate includes all remuneration paid to the employee for work performed:

• Mandatory Inclusions: Non-discretionary productivity and quality bonuses, attendance bonuses, shift differentials (e.g., night shift pay), hazard pay, and sales commissions.
• Statutory Exclusions (29 U.S.C. § 207(e)): Discretionary gifts, true expense reimbursements, paid time off (PTO, sick leave, unworked holidays), and previous premium pay for overtime.

2. California Overtime & Double-Time (Labor Code § 510)

California law provides significantly greater wage protections than the federal FLSA baseline. Under California Labor Code § 510 and Industrial Welfare Commission (IWC) Wage Orders, overtime is computed on both a daily and weekly basis:

Daily Overtime Beyond California

While the federal FLSA enforces overtime solely on a 40-hour weekly basis, three other jurisdictions enforce daily overtime thresholds alongside California:

• Alaska: Daily overtime after 8 hours in a day.
• Nevada: Daily overtime after 8 hours (with statutory conditions).
• Colorado: Daily overtime after 12 hours plus weekly overtime after 40 hours.

Who These Formulas Apply to — Exempt vs Non-Exempt

The statutory FLSA formulas and daily overtime rules detailed throughout this documentation apply to non-exempt employees (encompassing the vast majority of hourly wage earners). Exempt executive, administrative, and professional employees are not covered by FLSA overtime requirements; under federal baseline regulations, the FLSA salary threshold is $684/week ($35,568 annually) — a salaried worker below it is non-exempt and overtime-eligible regardless of job title or assigned responsibilities. To calculate overtime or evaluate exemption criteria for salaried personnel, see our dedicated salaried-employees calculator.

From Salary to Hourly, and from Week to Year

Translating salaries into hourly regular rates and standard annualized figures requires standardized payroll math:

• Salary to Hourly Regular Rate: A salaried non-exempt weekly salary converts to an hourly regular rate by dividing by 40 hours (California rule already on this page).
• Annualization Formulas: Annualization uses weekly × 52, bi-weekly × 26, and monthly = weekly × 52 ÷ 12 — NOT weekly × 4, because a calendar year contains 52.14 weeks rather than 48 weeks.
• Worked Example: A salary of $1,100/week converts as follows:
  $1,100/week = $57,200/year (57200), $28,600 bi-weekly (28600), $4,766.67/month (4766.67).

Check Your Own Paycheck in 4 Steps

Follow this 4-step process to verify your pay stub against the governing overtime equations:

1. (1) Write down the workweek: Identify your employer's designated, fixed 7-day workweek (168 consecutive hours). Employers cannot average two weeks or use an 80-hour bi-weekly period to avoid paying overtime.
2. (2) Total hours and straight-time pay: Calculate all physical hours worked within that specific 7-day period and determine straight-time pay, ensuring non-discretionary bonuses and shift premiums are included.
3. (3) Apply the worked-example math above: Compute the true regular rate (total straight-time compensation ÷ total hours) and apply 1.5× to all hours over 40 (or state daily overtime tiers where applicable).
4. (4) Compare each line to the pay stub and raise any mismatch with payroll the same day, with the math attached: Verify straight-time earnings, overtime premium hours, and withholding deductions, and immediately raise any discrepancy with payroll.

3. Federal Income Tax Withholding (2026 IRS Publication 15-T)

Federal income tax withholding calculations follow the percentage method defined in IRS Publication 15-T and official 2026 inflation adjustments published by the Internal Revenue Service. Income is annualized based on pay frequency (weekly, bi-weekly, semi-monthly, or monthly) after applying the 2026 standard deduction.

2026 Standard Deductions

2026 Single Filer Brackets

2026 Married Filing Jointly (MFJ) Brackets

2026 Head of Household Brackets

4. FICA Payroll Taxes (Social Security & Medicare)

The Federal Insurance Contributions Act (FICA) mandates two mandatory employee payroll deductions on earned income under Social Security Administration statutory tables:

• Social Security Tax (OASDI): 6.2% on all wages up to the 2026 wage base limit of $184,500. Any earnings exceeding $184,500 in 2026 are exempt from further Social Security employee withholding (maximum employee tax: $11,439.00).
• Medicare Tax (Hospital Insurance): 1.45% on all wages, with no annual wage cap.
• Additional Medicare Tax: An additional 0.9% (total 2.35%) applies to compensation earned in excess of $200,000 for single filers, or $250,000 for married filing jointly, under Internal Revenue Code § 3101(b)(2).

5. State Income Tax & Local Tax Withholding

State income tax calculations are maintained in versioned data tables verified directly against each state's Department of Revenue (DOR). Nine states have no wage-based state income tax, resulting in a flat $0 withholding:

Local Tax Modeling: Philadelphia City Wage Tax Example

For jurisdictions with municipal payroll taxes, our calculation engine models official municipal ordinances. For instance, under the City of Philadelphia Department of Revenue (City Council Bill 250195):

• Resident Rate: 3.735% on all gross compensation.
• Non-Resident Rate: 3.425% on compensation earned for work performed physically within Philadelphia.
• Effective Date: Rates took effect July 1, 2026. Payroll withholding follows the check date, not the pay period end date.

6. OBBBA § 225 "No Tax on Overtime" Deduction (2025–2028)

Section 225 of the One Big Beautiful Bill Act (OBBBA) introduced a below-the-line federal tax deduction claimed on Schedule 1-A for qualifying overtime pay premiums earned between January 1, 2025, and December 31, 2028:

• FLSA Premium Only: Only the federal 0.5× overtime premium slice qualifies for the deduction. California daily overtime premiums and double-time premiums above the 1.5× FLSA rate do not qualify under federal statutory definitions.
• Annual Caps: Up to $12,500 per year for Single filers, or $25,000 per year for Married Filing Jointly (MFJ).
• Income Phase-Out: The deduction begins phasing out at $150,000 Modified Adjusted Gross Income (MAGI) for Single filers and $300,000 for MFJ, phasing out at a rate of $100 per $1,000 in excess MAGI (fully phased out at $275,000 Single / $550,000 MFJ).
• Taxes Affected: Applies strictly to federal income tax. FICA taxes (Social Security and Medicare) and state/local income taxes are completely unaffected by the OBBBA deduction.

7. Scope Boundaries: What the Calculators Do NOT Do

To maintain transparency, it is essential to understand what is outside the scope of our automated personal estimators:

8. Verification Discipline & Source Tracking

We adhere to a strict verification protocol:

1. Primary Regulatory Sources: We link directly to official government bodies — irs.gov, dol.gov, dir.ca.gov, ssa.gov, and state revenue departments.
2. Auditable Dates: Every calculator page carries an active "Data last verified" stamp reflecting the last human audit of the underlying statutes.
3. Public Changelog: Whenever tax brackets, minimum wages, or payroll caps are adjusted, the revisions are logged with effective dates in our public Tax & Rate Changelog.