时间转小数计算器 — 小时 & 分钟转小数
将小时和分钟换算为工资核算、考勤表和计费所需的小数小时——或将小数小时换回 HH:MM 格式。输入 1:30 即得 1.5，输入 2.75 即得 2:45。结果即时更新。
Time to Decimal Hours
Enter hours and minutes to convert to decimal hours for payroll, timesheets, or billing.
Quick Reference Table
| Time (HH:MM) | Decimal Hours |
|---|---|
| 0:15 | 0.25 |
| 0:30 | 0.50 |
| 0:45 | 0.75 |
| 1:00 | 1.00 |
| 1:15 | 1.25 |
| 1:30 | 1.50 |
| 2:00 | 2.00 |
| 2:30 | 2.50 |
| 4:00 | 4.00 |
| 7:30 | 7.50 |
| 8:00 | 8.00 |
| 10:00 | 10.00 |
Frequently Asked Questions
如何将时间:分钟格式转换为十进制小时？
十进制小时 = 小时数 + 分钟数 ÷ 60。例如：1:30 = 1 + 30/60 = 1.5 小时；2:45 = 2 + 45/60 = 2.75 小时；0:15 = 0 + 15/60 = 0.25 小时。这种格式便于工资计算（时薪 × 十进制小时）。
如何将十进制小时转换为时:分格式？
小时数取整数部分为小时；小数部分乘以 60 得到分钟。例如：2.75 小时 = 2 小时 + 0.75×60 分钟 = 2 小时 45 分；3.333 小时 = 3 小时 + 0.333×60 ≈ 3 小时 20 分。
为什么薪资计算需要十进制时间？
计算工资时，时:分格式无法直接用于乘法运算。例如，时薪 $20，工作 2:30（2.5 小时），如果直接用 2.30 × 20 = $46（错误！），正确答案是 2.5 × 20 = $50。将时间转换为十进制格式是准确计算工资的关键步骤。
分钟转十进制的常用换算是什么？
常用换算：15 分 = 0.25；20 分 = 0.333；30 分 = 0.5；45 分 = 0.75；10 分 = 0.167；40 分 = 0.667；50 分 = 0.833。建议将此换算表收藏，或使用本计算器快速完成换算。
Time to Decimal Conversion Guide
Conversion Formula
Converting between HH:MM time and decimal hours is straightforward once you know the underlying formula.
Time to Decimal Hours
Divide the total minutes by 60 to get the decimal representation:
Example: 1 hour 45 minutes = 1 + (45 ÷ 60) = 1 + 0.75 = 1.75 decimal hours
Decimal Hours to Time
Separate the whole number (hours) from the decimal fraction, then multiply the fraction by 60:
Minutes = round((Decimal Hours − Hours) × 60)
Example: 2.25 decimal hours → Hours = 2, Minutes = round(0.25 × 60) = 2:15
Why This Matters
Clocks count time in base-60 (60 minutes per hour), but calculators, spreadsheets, and payroll systems work in base-10. Multiplying 1:30 × $20/hour incorrectly gives $1,030; the correct decimal conversion gives 1.5 × $20 = $30.
Common Conversions Table
Use this reference table for the most frequently encountered minute-to-decimal conversions:
| Minutes | Decimal (fraction of hour) | Fraction |
|---|---|---|
| 5 min | 0.0833 | 1/12 |
| 6 min | 0.1000 | 1/10 |
| 10 min | 0.1667 | 1/6 |
| 12 min | 0.2000 | 1/5 |
| 15 min | 0.2500 | 1/4 |
| 20 min | 0.3333 | 1/3 |
| 30 min | 0.5000 | 1/2 |
| 36 min | 0.6000 | 3/5 |
| 45 min | 0.7500 | 3/4 |
| 48 min | 0.8000 | 4/5 |
| 54 min | 0.9000 | 9/10 |
Note: 15 and 30 minutes are the most common values in payroll systems because they are exact quarters of an hour.
Payroll & Timesheet Use Case
Decimal hours are the standard format used by payroll software, billing systems, and project management tools because they allow straightforward multiplication with an hourly rate.
Step-by-Step Payroll Example
- An employee works from 9:00 AM to 5:45 PM — a total of 8 hours 45 minutes.
- Convert 8:45 to decimal: 8 + (45 ÷ 60) = 8.75 decimal hours.
- Multiply by hourly rate: 8.75 × $25/hr = $218.75 gross pay.
Common Timesheet Scenarios
| Clock Time | Decimal Hours | Pay @ $20/hr |
|---|---|---|
| 7:30 | 7.50 | $150.00 |
| 7:45 | 7.75 | $155.00 |
| 8:00 | 8.00 | $160.00 |
| 8:15 | 8.25 | $165.00 |
| 8:30 | 8.50 | $170.00 |
| 8:45 | 8.75 | $175.00 |
Rounding Rules in Payroll
Many US employers use the FLSA 7-minute rule: time worked up to 7 minutes is rounded down to the nearest quarter-hour; 8 minutes or more is rounded up. For example, 1 hour 7 minutes rounds to 1.00 hours, while 1 hour 8 minutes rounds to 1.25 hours (1:15). Always verify your employer's specific rounding policy.