Shift Differential Calculator
Estimate flat or percentage shift differential, blended regular rate, federal weekly overtime premium, and gross pay from one base rate and one differential.
Estimated gross pay
$442.00
48 total hours, including 8 overtime hours
- Differential pay
- $24.00
- Blended regular rate
- $8.50/hour
- Added OT premium
- $34.00
Straight-time earnings
- Base wages (48 hours)
- $384.00
- Differential ($1.00/hour for 24 hours)
- $24.00
- Straight-time earnings
- $408.00
Weighted-average overtime
- Blended regular rate
- $8.50/hour
- Additional half-time premium
- $34.00
- Estimated gross pay
- $442.00
Official U.S. Department of Labor sources
Weighted-average and differential treatment reviewed 2026-08-13. The default reproduces the Department's $442 night-shift example.
What this calculator assumes
- Overtime hours are already included within base-only plus differential hours; do not add them to total hours again.
- Straight-time compensation is already paid for every hour, so overtime adds one-half of the blended regular rate for each overtime hour.
- The model covers one base rate and one flat or percentage differential for a nonexempt weekly federal calculation.
- State daily overtime, double time, 8-and-80 plans, public-sector rules, prevailing wages, minimum wage, tips, bonuses, commissions, taxes, exemptions, and contract terms are excluded.
Formulas, assumptions, and rounding are documented in our calculator methodology.
Built and maintained by Will Henschell, Data Scientist. Editorial policy.
The Shift Differential Formula
For a flat premium, differential per hour is the entered dollar amount. For a percentage premium, it is base rate times the entered percentage. Differential pay equals that amount times qualifying hours. Add differential pay to base wages for straight-time earnings, divide by total hours for the blended regular rate, then add one-half of that rate for each overtime hour already included in total hours.
Weighted-Average Regular Rate
Federal regulation 29 CFR 778.115 generally says that when an employee works at two or more rates in one workweek, the regular rate is the weighted average: total earnings, except statutory exclusions, divided by total hours. This tool reaches the same result by adding base wages and shift differential before dividing by hours.
Why the Additional Premium Is Half-Time
Every entered hour already receives straight-time base pay, and qualifying hours also receive the differential. To bring overtime hours to one and one-half times the blended regular rate, the remaining addition is one-half of that rate. This method assumes the entered straight-time compensation is included in the regular rate and that no other premium credit changes the calculation.
What This Weekly Model Excludes
The result does not decide employee classification, overtime eligibility, minimum-wage compliance, or which hours qualify for a differential. It excludes state daily overtime, double time, 8-and-80 healthcare plans, public-sector rules, prevailing wages, tips, bonuses, commissions, multiple differentials, taxes, benefit deductions, and contract-specific methods.
Official Source Review - August 13, 2026
The calculation was reviewed against current 29 CFR 778.115 and 778.207 in the Electronic Code of Federal Regulations, U.S. Department of Labor Fact Sheet 54's $442 night-shift example, and Fact Sheet 56A's regular-rate overview. Current law, applicable state rules, and the employee's actual agreement should be checked before using the estimate for payroll decisions.
Frequently Asked Questions
- Multiply the additional dollar amount per hour by the hours worked on the qualifying shift. Then add that differential pay to base wages. For example, a $1 night differential across 24 hours adds $24 before any additional overtime premium.
- Multiply the base hourly rate by the differential percentage to find the added amount per qualifying hour, then multiply by differential hours. A 15% differential on a $32 base rate adds $4.80 for each qualifying hour.
- Ordinary night-shift differentials generally must be included when determining the regular rate under federal regulations. When an employee has different rates in one workweek, 29 CFR 778.115 generally uses a weighted average: total straight-time earnings divided by total hours. The additional overtime premium is then one-half that regular rate for hours over the applicable threshold when straight time is already paid.
- The base wages line pays the base rate for every hour, including overtime hours. The overtime line adds only the extra half-time premium needed to reach time and one-half of the blended regular rate. Adding overtime hours to the total a second time would double-count their straight-time pay.
- Yes. The default uses 24 hours at $8, 24 night hours at $9, and 8 overtime hours within 48 total hours. Straight-time earnings are $408, the blended regular rate is $8.50, the added overtime premium is $34, and gross pay is $442, matching DOL Fact Sheet #54.