Therapy Billing Units Calculator
Two quick answers: how many units a number of timed minutes supports, and how many minutes you need for a number of units. It uses Medicare’s 8-minute rule for timed outpatient therapy codes.
By the Best Therapy Productivity Calculator team · Last updated October 2026
Quick conversion table (Medicare 8-minute rule)
| Timed minutes | Units | Units | Minutes needed | |
|---|---|---|---|---|
| 15 | 1 | 1 | 8–22 | |
| 30 | 2 | 2 | 23–37 | |
| 40 | 3 | 3 | 38–52 | |
| 45 | 3 | 4 | 53–67 | |
| 50 | 3 | 5 | 68–82 | |
| 53 | 4 | 6 | 83–97 | |
| 60 | 4 | 7 | 98–112 | |
| 75 | 5 | 8 | 113–127 | |
| 90 | 6 |
Formula: units = full 15-minute blocks, plus one more if 8 or more minutes are left over.
Why a 50-minute and a 53-minute session bill differently
At 50 minutes you’re in the 38–52 range: 3 units. Three more minutes moves you to 53: 4 units. Your productivity counts every minute either way. Billing just works in steps.
That doesn’t mean sessions should be stretched to reach the next unit. Treatment length should follow the plan of care and medical necessity. CMS guidance also says sessions shouldn’t be structured to consistently average less than 15 minutes per timed unit.
Things the converter doesn’t do
- Allocate units across codes. For multi-code days, use the 8-minute rule calculator and your documentation.
- Untimed codes. Evaluations, SLP treatment (92507) and group (97150, 92508) are billed per session, not by units of time.
- Non-Medicare rules. Other payers may use different unit methods.
Frequently asked questions
How many units is 45 minutes of therapy?
3 units under the Medicare 8-minute rule.
How many minutes are 2 units?
23 to 37 minutes.
How many units is 1 hour?
4 units (60 falls in the 53–67 range).
Do PTA minutes convert differently?
No. Units are calculated the same way. Under Medicare Part B, services furnished in whole or in part by a PTA or OTA (beyond 10% of the minutes) carry the CQ or CO modifier and are paid at 85%.
Related: 8-minute rule calculator · CPT modifiers · Treatment minutes calculator
Educational tool, not billing advice.