DayFig's Payroll Hours Calculator and Time Card Calculator both expose an "Overtime Threshold" field that defaults to 40 hours per week. That default is not a guess — it is the federal standard set by the Fair Labor Standards Act (FLSA).
The Federal Overtime Rule (FLSA)
Under the FLSA, covered, non-exempt employees must receive overtime pay of at least one and one-half times (1.5×) their regular rate of pay for hours worked over 40 in a workweek. A "workweek" is a fixed, regularly recurring period of 168 hours (seven consecutive 24-hour periods); it does not have to match the calendar week, but it must be consistent. Employers may not average hours across two or more weeks to avoid overtime. (U.S. Department of Labor, Factsheet #23: Overtime Pay Requirements of the FLSA; 29 CFR Part 778.)
Two things the federal rule does not require: it does not mandate daily overtime (extra pay after 8 hours in a single day), and it does not set a maximum number of hours an employee aged 16 or older may work. There is also no federal requirement for a specific pay frequency — that is left to the states (see "Limits & Not-Applicable" below).
How the Calculator Maps the Rule
The otThreshold field is where the FLSA 40-hour line is applied. With the default of 40, a 45-hour week at $20/hour computes as:
- Regular: 40 hrs × $20 = $800
- Overtime: 5 hrs × $30 (1.5×) = $150
- Gross pay = $950
The optional Double-Time Hours field (default 0) models premium pay some employers or union contracts grant (for example, after 12 hours in a day). Federal FLSA law does not require double time, so it stays at 0 unless your employer or state provides it.
State Differences — The "Layered" Tuning
The 40-hour federal line is the floor, not the ceiling. Some states add daily overtime on top of the weekly rule:
- California (Labor Code §510): 1.5× for hours over 8 in a workday and over 40 in a workweek; 2× for hours over 12 in a workday or over 8 on the seventh consecutive day. (California DIR, Overtime FAQ.)
- Other states (for example Alaska) also recognize daily-overtime thresholds. Rules vary, so always check your state's Department of Labor.
Because a weekly-40 tool cannot represent a daily threshold, raise the threshold or note the difference manually when you are in a daily-overtime state. The calculator's threshold is a tuning knob, not a substitute for your state's law.
Limits & Not-Applicable Items
- Pay frequency: Federal law does not require employers to pay on a set schedule. Some states mandate weekly, bi-weekly, or semi-monthly pay. DOL confirms there is no federal frequency mandate — consult your state agency.
- Exempt employees: The 1.5× rule does not apply to salaried "exempt" employees who meet the salary and duties tests.
- Regular rate details: Bonuses, shift premiums, and multiple pay rates can change the "regular rate." Our tool uses a single flat hourly rate.
- Salary split across a >40-hour week: must be re-divided to find the regular rate (29 CFR 778.113) — not modeled here.
Disclaimer
DayFig is a date and math tool, not a payroll or legal advisor. This article summarizes public DOL guidance for general understanding and is not legal, tax, or payroll advice. For your specific situation, contact the U.S. Department of Labor Wage & Hour Division or a qualified professional.