Why Your Overtime Pay Was Lower Than You Expected
The most common causes are paid time off within the same week not counting toward the 40-hour overtime threshold (reducing actual overtime hours below what total paid hours might suggest), a misunderstanding of which base rate overtime is calculated from, or taxes taking a larger visible bite out of a larger-than-usual paycheck due to how payroll withholding estimates a full pay period's income.
An overtime paycheck that feels smaller than expected is usually explainable by one of these specific, common factors rather than a payroll error.
Paid time off not counting toward the threshold
As covered in the worked-example guide, only actually-worked hours typically count toward the 40-hour overtime threshold — a week that includes a paid holiday or sick day alongside extra work hours can have fewer qualifying overtime hours than the total paid hours for the week might suggest.
Confusion about the base rate
Overtime is calculated from the regular hourly rate, not from a rate that already includes any differential pay or bonus — if a specific base rate assumption is off, the calculated overtime premium will be off proportionally.
Withholding on a larger paycheck
Payroll withholding calculations often estimate annual tax liability based on that specific paycheck's amount extrapolated across a full year — a larger-than-usual paycheck (due to overtime) can trigger proportionally higher withholding for that pay period specifically, even though the actual annual tax liability calculation evens out over the full year, similar to the paycheck-withholding mechanics covered in the US paycheck guide.