Enter a time value into the calculator (and select seconds, minutes, or hours) to determine the time in units (decimal hours). This calculator can also evaluate either variable when the other is known.
- All Unit Converters
- Hours to Units Calculator
- Hours to Decimal Calculator
- Decimals to Time Calculator
- Tenth of an Hour Calculator
- Fraction of an Hour Calculator
Minutes to Units (Decimal Hours) Formula
The calculator uses a different formula for each mode.
Time to decimal hours, and HH:MM to decimal hours:
decimal_hours = hours + minutes/60 + seconds/3600
Decimal hours back to minutes:
minutes = decimal_hours * 60
Billing units from timed minutes:
medicare_8min: units = floor((minutes - 8) / 15) + 1, if minutes >= 8 floor_15: units = floor(minutes / 15) nearest_15: units = floor((minutes + 7.5) / 15)
- minutes = total timed minutes
- seconds = total seconds (only used if you enter seconds)
- hours = whole hours portion
- decimal_hours = hours expressed as a single decimal number
- units = whole billing units
- floor() = round down to the nearest whole number
The first tab converts a single time value (minutes, seconds, or hours) to decimal hours. The HH:MM tab adds the hour and minute parts before dividing the minute part by 60. The reverse tab multiplies decimal hours by 60 to get minutes. The billing tab applies one of three rounding rules to convert timed minutes into whole 15-minute service units.
Reference Tables
Use this table to convert minutes straight to decimal hours without running the math.
| Minutes | Decimal hours | Minutes | Decimal hours |
|---|---|---|---|
| 5 | 0.08 | 35 | 0.58 |
| 10 | 0.17 | 40 | 0.67 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 50 | 0.83 |
| 25 | 0.42 | 55 | 0.92 |
| 30 | 0.50 | 60 | 1.00 |
This table shows how the Medicare 8-minute rule converts timed minutes to billable units.
| Timed minutes | Billable units |
|---|---|
| 0 to 7 | 0 |
| 8 to 22 | 1 |
| 23 to 37 | 2 |
| 38 to 52 | 3 |
| 53 to 67 | 4 |
| 68 to 82 | 5 |
| 83 to 97 | 6 |
Examples and FAQ
Example 1. You worked 1 hour and 38 minutes. Convert to decimal hours: 1 + 38/60 = 1 + 0.6333 = 1.63 hours rounded to hundredths. Most timecards accept 1.63.
Example 2. A therapy session lasts 53 timed minutes under the Medicare 8-minute rule: floor((53 - 8) / 15) + 1 = floor(45/15) + 1 = 3 + 1 = 4 units.
Why do payroll systems want decimal hours? Decimal hours multiply directly by an hourly rate. With minutes, you would have to divide first, so most payroll software stores hours as a decimal number with two digits after the point.
How many decimals should you keep? Two decimals are standard for payroll. Four decimals avoid rounding drift if you add many short entries before reporting a total.
What is the difference between rounding down to 15 and the 8-minute rule? Rounding down to 15 gives no credit for 1 to 14 extra minutes. The 8-minute rule gives a unit once you cross 8 minutes into the next 15-minute block, so it tends to produce more units for the same time.
Can you mix seconds into a timecard entry? Yes. Convert seconds to minutes by dividing by 60, add to the minute total, then divide the whole thing by 60 to get decimal hours.
