Guide

Overtime pay basics

Overtime is not 1.5 times your hourly wage. It is 1.5 times your regular rate, and that includes shift differentials and nondiscretionary bonuses. Getting this wrong is the most common payroll error in existence.

Reviewed 20 August 2026 · gross estimates, not payroll or tax advice

The regular rate is the number that matters

Short answer

Overtime is not calculated on your hourly wage. It is calculated on your “regular rate”, which is total straight-time pay for the week divided by hours worked. Shift differentials and nondiscretionary bonuses go into that total, which is why overtime pay is often higher than people expect — and why underpaying it is one of the most common payroll errors there is.

Regular rate = Total straight-time earnings ÷ Total hours worked

Under the US Fair Labor Standards Act, non-exempt employees are owed at least 1.5× the regular rate for hours over 40 in a workweek. The federal rule counts by the week, not the day and not the pay period; several states add daily overtime rules on top.

The trap is the word “total”. Shift premiums, night differentials, production bonuses, attendance bonuses and commission all count toward straight-time earnings. Genuinely discretionary gifts, paid time off, and reimbursements generally do not.

What goes into the regular rate

PaymentIn the regular rate?Why
Hourly wagesYesThe obvious base
Shift differential (nights, weekends)YesCompensation for hours worked
Nondiscretionary bonus (production, attendance, quality)YesPromised in advance to induce performance
CommissionYesEarnings for work performed
Discretionary bonus (genuine surprise gift)NoNot promised, amount and timing at employer’s sole discretion
Holiday or vacation payNoNot payment for hours worked
Expense reimbursementsNoNot compensation
Gifts on special occasionsNoExcluded by statute
“Discretionary” has a narrow legal meaning. A bonus announced in advance — “$200 for perfect attendance this quarter” — is nondiscretionary no matter what the policy calls it, because employees worked toward it. Calling it discretionary in a handbook does not make it so.

Shift differentials

A shift differential is a premium for working undesirable hours. It is contractual, not statutory, in the US — there is no federal requirement to pay extra for nights or weekends, only for overtime hours.

TypeTypical sizeHow it is applied
Evening / swing shift5–10%, or $1–$2 per hourAdded to the base hourly rate for qualifying hours
Night / graveyard10–20%, or $2–$5 per hourSame, at a higher premium
Weekend10–15%Sometimes only Sunday, sometimes both days
Holiday1.5× to 2× baseContractual; usually stacks with overtime rules
On-call standbyFlat daily or weekly feeMay or may not count as hours worked, depending on restrictions

Percentage differentials and flat-rate differentials behave differently as wages rise: a 15% night premium grows with every pay rise, while “$3 an hour extra” quietly shrinks in real terms every year. If you are negotiating, the percentage is the better structure.

Worked example — where the extra money comes from

A production worker: 46 hours in the week, $20.00 per hour base, 12 of those hours on a night shift paying a $3.00 differential, plus a $100 nondiscretionary weekly production bonus.

1
Straight-time earnings. (46 × $20.00) + (12 × $3.00) + $100 = $920 + $36 + $100 = $1,056
2
Regular rate. $1,056 ÷ 46 hours = $22.96 per hour — not $20.00
3
Overtime premium. Straight time is already paid for all 46 hours, so the extra owed is the 0.5 premium on the 6 overtime hours: 6 × $22.96 × 0.5 = $68.88
4
Total week. $1,056 + $68.88 = $1,124.88
The error to look for
$8.88 underpaid per week

A payroll system that calculates overtime on the $20.00 base rate alone pays 6 × $20 × 0.5 = $60.00 instead of $68.88. Small per week, roughly $460 a year, and multiplied across a workforce it is the single most common wage-and-hour claim. Educational example only — not legal advice.

Model your own week in the overtime bonus calculator.

Bonuses earned over more than one week

A quarterly or annual nondiscretionary bonus still has to be included in the regular rate — retroactively, across every week of the period it covers.

The standard approach is to allocate the bonus evenly across the workweeks it was earned over, then recompute the overtime premium for any week containing overtime hours, and pay the difference. A $1,300 quarterly bonus over 13 weeks allocates $100 per week; each week with overtime then generates a small additional payment.

This is the most frequently missed obligation in US payroll. If you receive a nondiscretionary bonus and worked overtime during the period it covers, check whether a retroactive overtime adjustment appeared on a later payslip. Many employers simply never make it.

Outside the United States

The regular-rate mechanic above is specifically American. Elsewhere the shape is different:

United KingdomNo statutory overtime premium at all. Overtime rates are contractual. The binding rules are the National Minimum Wage (averaged across the pay reference period) and the 48-hour weekly limit under the Working Time Regulations, which can be opted out of individually.
European UnionThe Working Time Directive sets a 48-hour average weekly maximum and minimum rest periods. Overtime premiums come from national law or collective agreements and vary widely.
AustraliaOvertime rates are set by the relevant modern award or enterprise agreement, commonly 1.5× for the first two or three hours and 2× thereafter, with separate weekend and public holiday penalty rates.
CanadaProvincial. Typically 1.5× after 8 hours a day or 40–44 hours a week, with the exact threshold depending on the province.

This guide describes general principles for planning purposes. Wage and hour law is fact-specific and changes; for anything with money at stake, check the current rules in your jurisdiction or take professional advice.

Frequently asked questions

How is overtime pay calculated?

Under US federal law, at least 1.5 times the regular rate for hours worked over 40 in a workweek. The regular rate is total straight-time earnings for the week divided by hours worked, which includes shift differentials, commission and nondiscretionary bonuses - not just the base hourly wage.

Do bonuses count towards overtime pay?

Nondiscretionary bonuses do. A bonus promised in advance for production, attendance, quality or hitting a target must be included in the regular rate, and if it covers more than one week it has to be allocated back across those weeks with the overtime premium recalculated. Genuinely discretionary bonuses do not count.

What is a shift differential?

A premium paid for working less desirable hours such as nights, weekends or holidays. It is contractual rather than legally required in the US, usually 5-20% of the base rate or a flat amount per hour, and it must be included in the regular rate when overtime is calculated.

Does a shift differential increase overtime pay?

Yes. Shift differentials are part of straight-time earnings, so they raise the regular rate and therefore the overtime premium. Calculating overtime on the base hourly rate alone underpays the employee and is a common payroll error.

Is overtime calculated daily or weekly?

Federal US law counts by the workweek: hours over 40. Some states, including California, add daily overtime after 8 hours and double time after 12. Australia and several other countries use daily thresholds set by awards or agreements.

Do salaried employees get overtime?

It depends on whether they are exempt. In the US, exemption requires meeting both a salary threshold and a duties test - being paid a salary alone is not enough. Misclassification of salaried staff as exempt is one of the most common sources of wage claims.

Related tools and guides

Written and reviewed by the BonusPayCalc editorial team. Every formula on this site is shown on the page that uses it, so you can check it against your own plan document. Figures are gross planning estimates and not payroll, tax, legal or HR advice — see methodology.