How to calculate part-time therapy productivity on short, split and PRN shifts
The formula is the same on a short day, but fixed tasks take a bigger share of it.
Part-time therapy productivity uses the same formula as a full-time day: billable minutes divided by paid minutes. On a short shift, one cancellation or one fixed task takes a bigger share of the day, so the same target is harder to reach.
The figures on this page are worked examples with an 85% target. They follow US break rules unless they say otherwise. If you work elsewhere, use the breaks your contract says are paid. This is general information, not employment or legal advice, and your employer's rules decide how your minutes are counted.
Part-time therapy productivity: paid minutes on a short shift
For a part-time day, paid minutes is the shorter figure. In the US, short rest breaks of 5 to about 20 minutes count as hours worked, so they stay in paid minutes. A bona fide meal period, ordinarily 30 minutes or more, is not worktime, so it comes out.
- 4-hour shift, no break: 240 paid minutes. At 85%, you need 204 billable minutes.
- 5-hour shift with a paid 15-minute rest break: 300 paid minutes. At 85%, you need 255 billable minutes, and the break uses 15 of the 45 non-billable minutes you have.
- 6-hour shift with a 30-minute unpaid meal break: 330 paid minutes. At 85%, you need 281 billable minutes (280.5, rounded up so the target is met).
Outside the US, or where your contract makes a 15-minute break unpaid, take the break out of paid minutes. The same 5-hour shift is then 285 paid minutes and needs 243 billable minutes (242.25, rounded up).
The therapist productivity calculator works out any of these days, and the productivity with lunch break calculator takes an unpaid meal break out for you. Does a lunch break count against productivity? covers the break question in more detail.
Why short shifts are harder
Every fixed task in your day takes the same time whether you work four hours or ten. Handover, setting up, checking the schedule and the first note are all fixed tasks. On a short shift they are a much larger share of the total.
Example: your fixed tasks at the start and end of the day take 25 minutes in total.
| Shift | Paid minutes | 25 minutes as % of paid time | Highest possible productivity |
|---|---|---|---|
| 4 hours, no break | 240 | 10.4% | 89.6% |
| 6 hours, 30-minute unpaid meal break | 330 | 7.6% | 92.4% |
| 8 hours, 30-minute unpaid meal break | 450 | 5.6% | 94.4% |
| 10 hours, 30-minute unpaid meal break | 570 | 4.4% | 95.6% |
On a 4-hour shift you start nearly five points behind a colleague on an 8-hour shift (89.6% against 94.4%). That gap exists before either of you has treated anyone. A cancellation adds to the gap. A 45-minute slot is 18.8% of a 240-minute day and 10.0% of a 450-minute day.
If you are part-time on a full-time target, these numbers are a fair thing to raise with a manager.
Split shift productivity
A split shift is a morning segment and an evening segment with a long unpaid gap between them. Productivity for a split shift uses the total of the paid segments, and the unpaid gap stays out of the sum.
Example: three hours in the morning and three in the evening, with a 15-minute rest break in each segment. In the US those breaks are paid.
- Paid minutes: 360, including the two paid breaks
- At 85%: 306 billable minutes required
- Non-billable room: 54 minutes, and the two breaks take 30 of them
Fixed tasks happen twice on a split shift. With the same 25 minutes of fixed tasks in each segment, 50 minutes go before any treatment. Add the 30 minutes of paid breaks, and only 280 of the 360 paid minutes can be treatment. That is a ceiling of 280 ÷ 360 = 77.8%, so an 85% target can't be met on this schedule.
Where an employer's system leaves paid breaks out of paid minutes, the ceiling is 280 ÷ 330 = 84.8%. That is still under 85%.
PRN and per-diem work
Your PRN target may be set higher than your full-time colleagues' on the reasoning that PRN staff carry no administrative duties. Check whether you really have none by tracking your non-billable minutes for a few shifts.
A PRN clinician who covers three facilities also pays a learning cost in each unfamiliar building. It takes time to find the equipment, the charting system and the person to hand over to. Record those minutes.
Covering two settings in one day
When you split a day between two units or buildings, the travel between them is not treatment, so it is not billable. In the US, travel from one job site to another during the workday counts as hours worked, so it stays in paid minutes. Calculate the whole day as one denominator and treat the travel as a fixed task.
Example: a 450-minute day with 40 minutes of travel between sites caps you at (450 − 40) ÷ 450 = 91.1% before documentation. Add 40 minutes of on-the-clock notes and the ceiling is 370 ÷ 450 = 82.2%, below an 85% target. If that is your arrangement, the target and the schedule contradict each other, and it is worth putting that in writing. Productivity with travel time works through travel in more detail.
Comparing a part-time week with a full-time one
To compare your output with a full-time colleague's, convert both to minutes rather than percentages.
Annual billable minutes = daily billable minutes × days per week × 46
The 46 is this site's assumption for working weeks a year after leave and holidays. Use your own figure if it differs.
Example: three 4-hour days is 12 hours a week, which is 0.3 FTE against a 40-hour week. At 85%, that clinician delivers 204 billable minutes on each of three days, or 28,152 minutes a year. A full-timer on five 450-minute days at 85% delivers 383 a day, or 88,090 minutes a year.
The ratio of output is 28,152 ÷ 88,090 = 0.32. The ratio of paid minutes is also 0.32 (720 a week against 2,250), because both clinicians work at 85%. The part-timer's output matches their share of paid time almost exactly. The figure sits a little above 0.3 FTE because the full-timer's 30-minute unpaid meal breaks come out of their paid time.
This comparison shows a gap only when the two percentages differ. Compare output with the share of paid minutes rather than with FTE. Against FTE, the part-timer above looks slightly ahead (0.32 of the output on 0.3 FTE) when they are level with their share.
Making the case for a pro-rated target
If you work short shifts on a full-time target, the fixed-task table above is your case, and it can be checked. Ask for a target adjusted for the fixed tasks that don't scale with shift length.
With 25 minutes of fixed tasks, a 4-hour clinician loses 10.4% of the day to it and an 8-hour clinician 5.6%. A target about five points lower for shifts under five hours matches that gap. It is also a narrower request than a general reduction.
Job sharing and handover
When two part-time clinicians share a caseload, handover takes real time and is not billable. Fifteen minutes at each end of a shared day is 30 minutes of non-billable time that exists only because the post is shared. Raise it when the job share is set up, so the target allows for it from the start.
Comparing part-time offers
Convert both offers to paid minutes and treatment minutes per week rather than comparing percentages or headline hours. Example: three 8-hour days with a 30-minute unpaid meal break give 1,350 paid minutes (3 × 450). Five 4-hour days with no break give 1,200 (5 × 240). With 25 minutes of fixed tasks on each day, that leaves 1,275 minutes for treatment against 1,075.
On these figures, fewer and longer days leave more room to reach a productivity target. If your pattern is less regular, the weekly timesheet calculator totals a week of mixed shifts. The guide to weekly and pay period averages explains how to combine days of different lengths.