Shift differential calculator

Work out the extra gross pay for evening, night or weekend shifts. This free shift differential calculator takes a base hourly rate, the hours paid at the differential and either a fixed premium per hour or a percentage of the base rate, then shows the differential rate, the additional pay and the gross pay for those hours.

How to use the shift differential calculator

1. Enter the base hourly rate, before any premium.
2. Enter the hours worked during the shifts that earn the differential. Up to 168 hours, the hours in one week.
3. Enter the premium in one of two ways: a fixed amount per hour, such as $2, or a percentage of the base rate, such as 10%. Set the one you are not using to 0.
4. Select Calculate to see the differential per hour, the hourly rate for those hours, the additional pay and the gross pay for those hours. Use example loads the worked example below.

Calculate each kind of differential separately. If nights pay $2 an hour extra and Sundays pay 15%, run the calculator once for the night hours and once for the Sunday hours, using the policy your business has agreed.

Shift differential formula

Differential per hour = fixed premium, or base rate × percentage ÷ 100

Differential rate = base rate + differential per hour

Additional pay = differential per hour × differential hours

Gross pay for those hours = differential rate × differential hours

A 10% differential on an $18 base rate is $1.80 an hour, for a differential rate of $19.80. A percentage that gives a fraction of a cent, such as 7% of $17.25, is used unrounded, and the final amounts are rounded to the cent.

Worked example: $2 an hour for night shifts

A fictional sales associate earns $18 an hour and works 24 hours of night shifts in one week, with a $2 per hour night differential:

The result is additional pay of $48 for the week's night hours, on top of the $432 those hours earn at the base rate. Hours worked outside the differential shifts are paid at the base rate and are not part of this calculation.

Differentials, overtime and the rules that apply

How a differential is set, which hours earn it, and whether it applies to paid leave are decided by the employer's policy, an employment contract or a collective agreement, and by local law. Write down the rule, such as "$2 an hour for hours worked between 10 pm and 6 am", so everyone can check a payslip against it.

A differential can also change overtime pay. In the United States, federal rules include night shift differentials, paid as a percentage or as a fixed amount per hour, in the regular rate that overtime is based on; see 29 CFR 778.207. State law, other countries and agreements can differ. This calculator does not calculate overtime, taxes or deductions, and it is not legal advice.

Total a week's hours first with the timesheet calculator, and convert hours and minutes such as 7:45 into decimal hours with the hours-to-decimal converter. To compare a change to the base rate itself, use the pay raise calculator, and for a full weekly cost of a role, the staff cost calculator.

Frequently asked questions

Can I use the shift differential calculator without an account?

Yes. Enter the figures and calculate. Nothing is saved or sent, so use Copy result if you want to keep the figures.

Can I enter both a fixed premium and a percentage?

No. Use one method per calculation and set the other to 0. If a policy combines both, calculate each part separately and add the additional pay.

What is a typical shift differential?

There is no single standard amount. Differentials are set by each employer or agreement, and many are a fixed amount per hour or a percentage of the base rate. Use the rate in your own policy.

Does it work for weekly or monthly pay?

It works from an hourly rate. For a salaried role, use the hourly equivalent your payroll uses and the hours that earn the differential.

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