Methodology: How Our Calculators Work
This page lists every formula, definition and rounding rule our calculators use, so you can check any result by hand.
By the Best Therapy Productivity Calculator team · Last updated October 2026
Definitions
| Term | Meaning on this site |
|---|---|
| Billable minutes | Minutes your employer counts as productive. Usually direct treatment and evaluations. Some employers also count documentation or meetings. |
| Paid minutes | All the time you’re paid for, including paid short breaks. Excludes unpaid lunch. |
| Productivity % | Billable minutes ÷ paid minutes × 100 |
| Non-billable minutes | Paid minutes − billable minutes. Time for notes, setup, transitions and meetings. |
| Unpaid break | A break where you’re fully off duty and not paid. Under federal guidance, meal periods are typically 30 minutes or more. |
| Clock-out time | Start time + paid minutes + unpaid breaks |
Formulas
End time from a productivity target
Used by: Therapy Productivity Calculator, Productivity Calculator with Lunch Break
- Paid minutes = billable minutes ÷ (target % ÷ 100)
- Clock-out time = start time + paid minutes + unpaid breaks
Productivity percentage
Used by: Productivity Percentage Calculator
- Productivity % = billable minutes ÷ paid minutes × 100
- Billable minutes needed = paid minutes × (target % ÷ 100)
Time left in a shift
Used by: Clock-Out Time Calculator
- Paid time done = (current time − clock-in time) − unpaid breaks taken
- Paid time left = required paid time − paid time done
- Clock-out time = clock-in time + required paid time + all unpaid breaks
Rounding rules
| Calculation | Rounding | Why |
|---|---|---|
| Paid minutes from a target | Rounded down to the whole minute | Fewer paid minutes keeps you at or slightly above your target |
| Billable minutes needed for a target | Rounded up to the whole minute | You never fall a fraction short |
| Productivity % | Shown to one decimal place | Matches how most reports display it |
Example: 375 billable minutes at 85% = 441.18 paid minutes, so we show 441 minutes (7 h 21 min). Check: 375 ÷ 441 = 85.03%, which is at or above 85%.
Times past midnight
If a result crosses midnight, it’s labeled “next day.” For overnight shifts, the clock-out calculator has an option to treat a current time earlier than clock-in as the next day.
Worked examples you can check
| Start | Billable min | Target | Unpaid lunch | Paid time | Clock-out |
|---|---|---|---|---|---|
| 7:30 AM | 375 | 85% | 0 | 441 min (7 h 21 min) | 2:51 PM |
| 7:30 AM | 375 | 85% | 30 min | 441 min | 3:21 PM |
| 8:00 AM | 408 | 85% | 0 | 480 min (8 h) | 4:00 PM |
| 7:00 AM | 330 | 78% | 0 | 423 min (7 h 3 min) | 2:03 PM |
| Billable min | Paid min | Productivity |
|---|---|---|
| 396 | 480 | 82.5% |
| 408 | 480 | 85.0% |
| 384 | 480 | 80.0% |
What our calculators don’t do
- They don’t decide what counts as billable. That’s your employer’s policy.
- They don’t calculate pay, overtime or Medicare billing units (separate billing tools are coming soon).
- They don’t store your data. Everything runs in your browser.
Sources for definitions
- U.S. Department of Labor, Fact Sheet #22: Hours Worked Under the FLSA (rest and meal periods)
- ASHA, Productivity in Health Care Settings
Spotted an error in our math? Tell us. We’ll fix it and note the correction.