Why a Raise Mid-Year Complicates Overtime Math
When you work at the same hourly rate all year, your overtime premium is simple: 0.5 times your rate, times your overtime hours, times 52 weeks. But when your rate changes partway through the year — a raise, a promotion, a shift to a new position — there's no single "overtime rate" that applies to the whole year.
Overtime is calculated using the regular rate of pay in effect during the specific workweek the overtime was earned. Each workweek stands on its own. You cannot average your old and new rates together and apply one blended figure to all your overtime hours for the year.
Scenario 1: Your Raise Was Applied on Time
This is the straightforward case: your employer correctly started paying the new rate (and the correct new overtime rate) from the effective date forward. Every workweek before the raise uses the old rate for overtime; every workweek after uses the new rate.
Worked Example
A worker earns $18/hour through June 14, then gets a raise to $23/hour effective June 15. They work 44 hours in both the last week before and the first week after the raise.
Week of June 8–14 (before the raise), 44 hours:
- Regular pay: 40 × $18 = $720
- Overtime pay: 4 hrs × $18 × 1.5 = $108
- Total: $828
- Deductible OT premium (for the tax deduction): 4 hrs × $18 × 0.5 = $36
Week of June 15–21 (after the raise), 44 hours:
- Regular pay: 40 × $23 = $920
- Overtime pay: 4 hrs × $23 × 1.5 = $138
- Total: $1,058
- Deductible OT premium (for the tax deduction): 4 hrs × $23 × 0.5 = $46
The two weeks look identical in terms of hours worked, but the overtime pay is $30 more in the second week because the rate changed. You cannot simply average $18 and $23, apply $20.50 to all 8 overtime hours, and get the right number — each week must use its own rate.
Scenario 2: Your Raise Was Applied Late (Retroactive Correction)
This is a different situation: your raise was approved effective on one date, but payroll didn't implement it until a pay cycle or two later. Some of your paychecks were still at the old rate when they should have been at the new rate. This is a common payroll occurrence — not something to be alarmed about — but it affects overtime pay specifically, not just straight-time pay.
When a retroactive raise is paid, the employer owes more than just the regular-pay difference. Every overtime hour worked during the retro period was paid at 1.5× the old rate and now needs to reflect 1.5× the new rate. Because the employee already received the 1× portion, the additional amount owed is the 0.5× premium portion of the rate increase, applied to each overtime hour in the affected period.
Worked Example
A worker's rate goes from $18/hour to $20/hour, retroactively effective 4 weeks ago. In one of those affected weeks, they worked 6 overtime hours.
- Rate increase: $20 − $18 = $2/hour
- Originally paid for those OT hours: 1.5 × $18 × 6 = $162
- Correct OT pay at the new rate: 1.5 × $20 × 6 = $180
- Additional amount owed: $180 − $162 = $18
That $18 breaks down as: the straight-time difference ($2 × 6 = $12) plus the overtime premium difference (0.5 × $2 × 6 = $6). This retro correction should appear on the next regular paycheck after the employer can compute and arrange the payment.
If you receive a retro-pay check that looks slightly larger than just "hours × rate difference," the extra amount is likely the overtime premium correction — it's owed, and it's correct.
How to Find Your Old Rate If You Don't Have the Paperwork
If you need to figure out which rate was in effect during a particular period and you don't have an offer letter or rate-change notice handy:
- Check old pay stubs — most show your hourly rate or can be reverse-calculated from hours and gross pay
- Year-end pay summary — some employers provide an annual breakdown of earnings by pay period
- Ask payroll or HR — request a list of pay rate effective dates for the year. This is standard information they should be able to provide.
Why This Matters for Your Tax Deduction
If you're claiming the No Tax on Overtime deduction, a mid-year rate change means you cannot enter one premium figure for the whole year. The deductible premium portion is 0.5× the regular rate in effect × overtime hours — and if your rate changed, you need to calculate that premium separately for each rate period.
What to do: gather your pay stubs from before and after the rate change. Calculate the deductible premium for each period separately (overtime hours × 0.5 × the rate that was in effect), then add the two figures together. Enter that combined total into the deduction calculator as your annual overtime premium pay.
Using the Scenario 1 example above: the deductible premium for weeks at $18/hr plus the deductible premium for weeks at $23/hr, added together, gives you the correct annual figure. Averaging the two rates and applying one number would give an incorrect result.
Related Guides
- Overtime Pay Calculator — calculate your overtime for a typical workweek at your current rate
- No Tax on Overtime Calculator — estimate your federal overtime tax deduction (remember to split by rate period if your rate changed during the year)
- Multiple Pay Rates Overtime — a related but different scenario: working at two rates simultaneously in the same week (e.g., travel rate vs. work rate) uses a weighted average, while a rate change over time (this article) means each week simply uses the rate that was in effect