Your employer might call it a differential, a premium, or a bonus — and it can feel confusing when the terms seem to overlap. Here's the clear answer, plus how each one is actually taxed.
Shift differential, shift premium, and shift bonus almost always describe the exact same thing: shift differential pay — extra pay added to your base hourly wage for working a less desirable shift, such as nights, weekends, or holidays. Different employers and industries just use different words for it — the underlying pay mechanic doesn't change.
The terminology mostly comes down to habit rather than any legal or technical distinction:
None of these terms are defined or regulated by federal law, so an employer is free to use whichever one it prefers in its own policy documents.
This is the one distinction actually worth understanding, because it affects how your pay is taxed:
| Shift Differential / Premium / "Bonus" | True Bonus | |
|---|---|---|
| When it's paid | Every pay period, tied to hours worked | One-time or occasional |
| How it's taxed | As regular wages, at your normal rate | Often at the IRS supplemental wage rate |
| Counts toward overtime? | Yes, always | Sometimes, depending on the bonus type |
In other words, calling it a "shift bonus" is just a nickname — for pay and tax purposes, it behaves exactly like a shift differential, not like a discretionary or holiday bonus.
If you're trying to figure out what your own paycheck is referring to, industry is a decent clue:
Whatever the label, check your pay stub for a separate line item, or ask HR to confirm — the calculation method is what actually matters.
No matter what your employer calls it, the math is the same: it's either a percentage added to your base rate, or a flat dollar amount added per hour, multiplied by the qualifying hours you worked. Our shift differential calculator handles both formats automatically. For the full walkthrough with worked examples, see our step-by-step calculation guide.
Enter your rate, hours, and differential percentage or flat amount, and get your exact pay breakdown instantly.
Open the Shift Differential CalculatorThis article is for informational purposes only and isn't legal or payroll advice. Confirm your specific pay policy with your employer or HR department.
New to the term? Start with the plain-English definition, who qualifies, and typical rates.
Read GuideThe full step-by-step calculation, with worked examples.
Read GuideLearn exactly which hours count as night shift and how to calculate them.
Read GuideDoes overtime include your differential? Yes — here's the FLSA rule explained.
Read Guide