How to Calculate Part Time Monthly and Annual Income

Ever wondered how much that part-time gig actually pays over the course of a year? It’s not as straightforward as multiplying hourly wage by hours per week — there are a few variables that can make a big difference.

Part-time income is hourly wage × hours per week × weeks worked per year. A worker at $18/hour for 25 hours a week, 52 weeks a year, earns $23,400 gross. Monthly income is annual ÷ 12, or $1,950/month.

The Part-Time Income Formula

Part-time workers don’t earn a flat annual salary. Annual income depends on three variables:

Annual = Hourly wage × Hours per week × Weeks worked per year
Monthly = Annual ÷ 12

A $18/hour worker scheduled for 25 hours/week, 52 weeks/year earns:

• $18 × 25 × 52 = $23,400/year
• $23,400 ÷ 12 = $1,950/month

A $15/hour worker at 20 hours/week earns $15,600/year, or $1,300/month. A $20/hour worker at 28 hours/week earns $29,120/year, or $2,427/month.

What Counts as Part Time?

There’s no single federal definition. The Affordable Care Act (ACA) defines full-time as 30 hours/week or more, so anything below 30 is treated as part-time for employer mandate purposes. The FLSA doesn’t define part-time at all.

In practice, part-time usually means under 30–35 hours/week. Workers at 25 hours are clearly part-time. Workers at 32 hours might be classified part-time by the employer but close to full-time hours.

The ACA 30-hour threshold matters because employers with 50+ full-time-equivalent employees must offer health coverage to anyone averaging 30+ hours/week. Many employers cap part-timers at 28–29 hours to avoid triggering the mandate.

Actually, I had a client who worked 29 hours a week at a retail store for three years. They were consistently denied health insurance because they were “part-time,” even though they worked nearly full-time hours. That’s exactly the kind of situation the ACA was meant to address, but the 30-hour loophole still exists.

Weekly vs Annual Hours

If you take unpaid time off, your annual hours drop. A part-timer scheduled 25 hours/week but taking 4 weeks unpaid leave works 48 weeks:

• $18 × 25 × 48 = $21,600/year (not $23,400)

If you work 50 weeks with 2 weeks unpaid PTO: $18 × 25 × 50 = $22,500/year.

If your employer offers paid time off, the PTO hours are paid at your regular rate and added to the total.

Monthly Income Reality Check

The annual ÷ 12 figure smooths income into equal monthly buckets, but cash flow doesn’t arrive that way. Some months have 5 weekly paydays; others have 4. A $1,950/month average might arrive as four $487 weekly checks one month ($1,948) and five the next ($2,435).

For budgeting, divide monthly needs by your typical paycheck size and plan around the average. The 50/30/20 budget rule on $1,950/month gives roughly $975 needs, $585 wants, $390 savings — but part-time income often barely covers needs.

ACA Benefit Eligibility Threshold

If you average 30+ hours/week over a measurement period (often 3–12 months), your employer must offer ACA-compliant health coverage. Below 30 hours, coverage is optional. This is why the income calculation matters: working one extra shift a week can push you over the threshold and trigger eligibility — or, for employers managing costs, push you into a cutback.

Overtime Still Applies

Part-time workers are non-exempt by default and earn overtime at 1.5× for hours over 40 in a workweek. Working 40 hours is rare for part-timers, but if you pick up extra shifts and cross 40, the premium kicks in. A $18/hour part-timer working 45 hours one week earns ($18 × 40) + ($18 × 1.5 × 5) = $720 + $135 = $855 that week.

The FLSA salary exempt threshold of $35,568/year (effective May 15, 2026) means part-timers earning $23,400 are non-exempt and overtime-eligible regardless of job duties.

State Minimum Wage Floor

Federal minimum wage is $7.25/hour, unchanged since 2009. Many states set higher floors: California $16/hour, Washington $16.66/hour, New York $15.50/hour. A 25-hour part-timer at the California floor earns $16 × 25 × 52 = $20,800/year — nearly triple the federal-floor equivalent of $9,420.

Does this mean you should move to California for a part-time job? Probably not, since cost of living is much higher. But it’s worth checking what your state’s minimum wage is before accepting a part-time gig.

Plan Your Numbers

Estimate annual and monthly totals with the part-time salary estimator, then check benefit-eligibility math with the full-time equivalent calculator.