About the Shift Differential Calculator
Many employers pay a shift differential — an extra amount per hour for evening, night, weekend or holiday shifts. This shift differential calculator works out your hourly rate on premium shifts, how much extra the differential adds each week and year, and your total weekly pay including overtime.
It is built for nurses, warehouse and manufacturing staff, security officers, call-centre agents and anyone comparing a day schedule with nights. Enter your base rate, choose a flat premium (for example $2.50 an hour) or a percentage (for example 10%), and split your hours between standard and differential shifts.
Overtime follows the US Fair Labor Standards Act method: shift differentials are part of the “regular rate”, so overtime hours earn an extra half of your blended average hourly rate, not just half of your base rate. Hours above the weekly threshold (40 by default) count as overtime.
With the default inputs, the total weekly pay is $1,105.00. Change any value above to recalculate instantly.
How to use the shift differential calculator
- 1Enter your base hourly rate.
- 2Choose a flat or percentage differential and enter the amount.
- 3Split your weekly hours between standard and differential shifts.
- 4Check the overtime threshold (40 hours under US federal law).
- 5Read your weekly pay, shift rate and how much the differential adds each year.
Formula and method
Straight-time pay is every hour at the base rate plus the differential for each hour worked on a premium shift. Under the FLSA, shift differentials must be included in the regular rate of pay, so the regular rate is total straight-time pay divided by total hours worked — a weighted average of your base and shift rates.
Hours above the overtime threshold have already been paid at straight time, so the overtime premium adds half of the regular rate for each overtime hour, making them 1.5 × the blended rate in total. Annual pay multiplies the weekly figure by the weeks you work.
- Base
- Base hourly wage
- Differential
- Extra pay per hour on premium shifts
- OT hours
- Total weekly hours above the overtime threshold
Worked examples
$20 base, $2.50 night differential, 48-hour week
48 hours at $20 is $960, plus $2.50 × 24 night hours = $60, so straight-time pay is $1,020. The regular rate is $1,020 ÷ 48 = $21.25, and 8 overtime hours add 0.5 × $21.25 × 8 = $85, for $1,105 a week or $57,460 a year.
Nurse with a 15% night differential, 36 hours
A 15% differential on $42 is $6.30, so night shifts pay $48.30 an hour. Three 12-hour nights (36 hours) earn $1,738.80 a week, of which $226.80 is differential — $11,793.60 a year over 52 weeks.
Frequently asked questions
What is a shift differential?+
A shift differential is extra pay for working less desirable hours such as evenings, nights, weekends or holidays. It is usually a flat amount per hour (for example $1–$5) or a percentage of the base rate (often 5%–15%).
Are shift differentials required by law?+
No. US federal law does not require extra pay for night or weekend work; differentials are set by employer policy or union contracts. Once paid, though, they must be included when calculating the overtime rate.
Is shift differential included in overtime pay?+
Yes. Under the FLSA the regular rate includes shift differentials, so overtime is 1.5 × the blended regular rate. Using only the base rate underpays overtime and is a common wage-and-hour violation.
What is a typical night shift differential?+
Night differentials commonly run about 10% of base pay or $1–$3 an hour in many industries. Hospitals often pay more for nurses, and US federal employees under the General Schedule receive a 10% night differential for work between 6 p.m. and 6 a.m.
How do I calculate a percentage shift differential?+
Multiply your base rate by the percentage and add it to the base. A 10% differential on $25 an hour is $2.50, so the shift rate is $27.50 an hour.