Shift Differential Calculator: Night Shift & Overtime Pay

How the shift differential calculator works

A shift differential, also called a shift premium, is extra pay attached to eligible hours such as evening, night or weekend work. This calculator accepts the premium either as a percentage of the base hourly rate or as a fixed amount per hour.

You can enter regular and overtime hours separately. Because payroll policies and legal rules do not all treat the differential the same way when calculating overtime, the calculator makes that choice visible instead of assuming one rule.

Shift differential formulas

Percentage differential per hour: base hourly rate × differential percentage ÷ 100.

Fixed differential per hour: the entered fixed premium.

Shift hourly rate: base hourly rate + differential per hour.

Regular shift pay: shift hourly rate × regular eligible hours.

If the differential is included in the overtime-rate base, overtime shift pay = shift hourly rate × overtime multiplier × overtime hours.

If the differential is excluded from the multiplier, overtime shift pay = (base hourly rate × overtime multiplier + differential per hour) × overtime hours.

Differential premium shown: total shift pay − pay for the same hours at the base rate and entered overtime multiplier.

Checked example

Suppose the base rate is US$25 per hour, the differential is 12%, regular eligible time is 32 hours, overtime time is 8 hours and the overtime multiplier is 1.5.

The differential is US$25 × 12% = US$3 per hour, so the shift rate is US$28 per hour. Regular pay is US$28 × 32 = US$896. If the differential is included in the overtime-rate base, overtime pay is US$28 × 1.5 × 8 = US$336. Total gross shift pay is US$1,232.

The same hours without a differential would pay US$25 × 32 + US$25 × 1.5 × 8 = US$1,100. Therefore, the differential increases the result by US$132. If the multiplier applies only to the US$25 base rate, overtime pay becomes (US$25 × 1.5 + US$3) × 8 = US$324, total pay becomes US$1,220 and the premium is US$120.

What to confirm before using the result

• Confirm which hours qualify for the shift differential. The calculator does not infer eligibility from clock-in or clock-out times.
• Confirm whether the differential is a percentage or a fixed amount and whether it is included in the overtime-rate base.
• Enter only hours covered by the same base rate, differential and overtime rule. Calculate separate groups when rates differ.
• The result is gross pay before taxes, deductions, benefits, bonuses, meal penalties or other additions.
• This is an arithmetic estimate, not payroll, tax or legal advice. Employment agreements, collective bargaining terms and applicable law can require a different method.

Frequently asked questions

Is shift differential the same as overtime?

No. A differential is extra compensation for an eligible shift. Overtime is additional compensation tied to overtime hours and an applicable multiplier. Both can apply to the same hours.

Can I enter a 10% or 15% night premium?

Yes. Choose percentage mode and enter 10 or 15. The calculator converts that percentage into a per-hour premium using the base hourly rate.

Can I enter a fixed night premium such as US$2 per hour?

Yes. Choose fixed amount per hour and enter 2. The currency selector changes formatting only and does not convert exchange rates.

Should the shift differential be multiplied for overtime?

That depends on the applicable payroll rule. Use the visible overtime-basis selector to model either method, then confirm the choice with the employer's policy or a qualified payroll professional.

Related calculators

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