Before you say yes, turn the offer into one number: gross pay, minus the payroll taxes you can compute, minus the costs the shift creates. Six hours at Washington's 2026 minimum wage of $17.13 an hour is $102.78 gross (Washington State Department of Labor & Industries), and the IRS sets the employee's share of Social Security at 6.2 percent and Medicare at 1.45 percent, so 7.65 percent of that is $7.86 (IRS). The condition that changes everything: if the hours push you past 40 in the workweek, the DOL's overtime fact sheet puts them at time and one-half the regular rate, which turns the same six hours into $154.17 (Fact Sheet #23).
Confirm the rate before the hours
Ask which rate applies before you ask anything else, because an extra shift does not automatically carry a premium. The federal trigger is weekly, not daily: the DOL's overtime fact sheet defines the workweek as a fixed and regularly recurring period of 168 hours, seven consecutive 24-hour periods, and requires time and one-half only for hours over 40 inside it (Fact Sheet #23). A sixth shift in a week you were already scheduled for 36 hours is partly straight time and partly overtime; the same shift added to a 24-hour week is all straight time.
Then confirm start, finish, location and whether the finish is final. A shift that replaces another day and a shift that adds to the week are different offers with the same wording, and only one of them changes your total hours.
Subtract the payroll taxes you know
Two deductions are the same for almost everyone and you can do them on your phone. The IRS states the employee rate at 6.2 percent for Social Security, on earnings up to the 2026 wage base of $184,500, and 1.45 percent for Medicare with no wage cap, plus an Additional Medicare Tax of 0.9 percent on wages above $200,000 in a calendar year (IRS). For an ordinary extra shift, 7.65 percent is the figure to subtract.
Income tax withholding, benefit deductions and anything your state adds are not in that 7.65 percent, so treat the result as an upper bound rather than take-home pay. It is still a far better number than the gross, and it is the number worth writing on the offer.
Count the costs the shift creates
List only what the shift adds: the extra travel, the paid care you would not otherwise buy, the meal you would not otherwise pay for. Leave your ordinary household spending out of it — the question is what this shift changes, not what your month costs. The CFPB's Your Money, Your Goals toolkit publishes 43 tools and handouts, among them an income and benefits tracker, a spending tracker and a bill calendar, and the spending tracker is the one that already has these categories (CFPB).
Then add the hours that are not paid: travel each way, the handoff at either end, the shower and the wind-down. That figure does not change the wage; it changes what the day cost you, and it is the one people leave out.
Example: six hours at $17.13
Example. A Saturday shift, 2 pm to 8 pm, six hours, straight time, and you are at 30 hours for the week already. Gross: 6 × $17.13 = $102.78 (Washington State Department of Labor & Industries). Social Security and Medicare at 7.65 percent: $7.86 (IRS). That leaves $94.92 before income tax withholding.
Now the costs the shift creates: $12 of travel and $30 of agreed care is $42, so the shift is worth about $52.92 for the day. Against that, count 6 hours of work, 1 hour of travel and 30 minutes of handoff, which is 7.5 hours away from home — about $7.06 an hour once you divide the $52.92 by the time the day actually takes. The wage did not change. The comparison did. If those six hours had landed above 40 in the week instead, the DOL's overtime rate of time and one-half would make the gross $154.17 and the same subtraction would leave roughly $100 for the day (Fact Sheet #23). That is the difference worth one question to the scheduler. The longer version of this arithmetic, applied to a whole month, is the true cost of extra work.
Check the 10 hours the shift leaves you
Rest is a quantity, so write it as one. NIOSH's fatigue guidance recommends a minimum of 10 hours off between shifts in each 24-hour period, 7 or more hours of sleep plus recovery time each day, short breaks every two hours, and limiting extended shifts over 12 hours (NIOSH). An 8 pm finish followed by a 6 am start is 10 hours door to door on paper and closer to 8 once travel is counted, which is the gap to put in the reply.
If the shift displaces the only full day off in the week, that is the other figure to name. NIOSH's guidance also recommends one full day of rest per seven days (NIOSH), and a day off spent on a sixth shift is not the same day off, which is the whole subject of a day off that is not another shift.
The reply, with its condition
Answer in one message with the condition attached, not after:
"I can take Saturday 2 pm to 8 pm if the 8 pm finish is confirmed, since I open at 6 am Sunday. Is this shift at straight time or does it cross 40 hours this week?"
If you decline, decline plainly; no invented appointment is required, and a short factual no is easier to repeat next month. If you accept, save the confirmed start, finish and rate in the same place as the roster, because the thing you will want in three weeks is what you were told, in writing, before the shift.