# Shift Differential Calculator

> Work out the hourly rate and extra pay for night, evening or weekend shifts with a percentage or flat differential, and your blended rate for the week.

Category: Salary, HR & payroll · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/shift-differential-calculator

A shift differential adds a premium to your base rate for less popular hours. Enter it as a percentage or a flat amount per hour to see the shift rate and the total for a mix of shifts.

Also called: Shift premium calculator, Night differential calculator.

## Inputs
- Base hourly rate (default 20)
- Differential type (options: Percentage, Flat per hour; default percent)
- Differential (default 10)
- Hours on the differential shift (unit hours; default 24)
- Hours at the base rate (unit hours; default 16; optional)
- Currency

## Results
- Total gross pay
- Differential shift rate
- Extra pay from the differential
- Blended hourly rate

## Formula

```
Shift rate = Base × (1 + Differential% ÷ 100) or Base + Flat;  Total = Base × All hours + (Shift rate − Base) × Shift hours;  Blended = Total ÷ All hours
```

Where:
- Base: regular hourly rate
- Shift hours: hours worked on the shift that attracts the differential

## Worked example
1. Shift rate = 20 × 1.10 = $22 an hour.
2. Premium = (22 − 20) × 24 = $48.
3. Total = 20 × 40 + 48 = $848, a blended $21.20 an hour.

**Result:** A 10% night differential on 24 of 40 hours at $20 adds $48, for $848 gross.

## What the result means

The blended rate is useful when comparing a rota with mixed shifts against a day-only job. In some jurisdictions the differential must also be included in the regular rate used for overtime.

## Assumptions and limits
- All hours are straight-time hours; overtime is not included.
- Differentials that apply only to part of a shift (for example after 10 pm) need the hours entered accordingly.

## Questions

### Is a flat or percentage differential better?

A percentage grows with your base rate; a flat amount does not. At a $20 base, 10% and $2 are the same; at $30, 10% is worth $3.

### Does shift differential affect overtime?

Often yes: some laws, including US federal rules, require shift premiums to be counted in the regular rate on which overtime is calculated.

## Related calculators
- [Overtime Pay Calculator](https://calculators.geekmidst.com/calculators/overtime-pay-calculator)
- [Employer Cost of Employee Calculator](https://calculators.geekmidst.com/calculators/payroll-employer-cost-calculator)
- [Percentage Calculator](https://calculators.geekmidst.com/calculators/percentage-calculator)

_This calculator gives estimates for planning. It is not financial advice, and lenders’ actual terms, fees and rounding may differ._

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/shift-differential-calculator