Hours and Minutes to Decimal Converter

Convert between hours:minutes time format and decimal hours for payroll, billing, or project calculations.

Hours:Minutes (HH:MM)

Decimal Hours

Notes:

For time input, use the format HH:MM (e.g., 1:30, 08:45, 23:15)
Decimal results show hours with decimal fractions (e.g., 1.5 hours = 1 hour and 30 minutes)
Commonly used for payroll, billing, and timesheet calculations
To convert minutes to decimal hours, divide minutes by 60 (e.g., 45 minutes = 45/60 = 0.75 hours)

Understanding Time Format Conversion

Time is commonly expressed in two formats: the traditional hours and minutes format (HH:MM) and decimal hours. Converting between these formats is essential for many professional and personal applications, from calculating work hours for payroll to determining billing rates or managing project timelines.

How to Convert Hours and Minutes to Decimal Hours

Converting from hours:minutes format to decimal hours requires a simple mathematical calculation:

Formula:

Decimal Hours = Hours + (Minutes ÷ 60)

Examples:

1 hour and 30 minutes (1:30) = 1 + (30 ÷ 60) = 1 + 0.5 = 1.5 hours
2 hours and 45 minutes (2:45) = 2 + (45 ÷ 60) = 2 + 0.75 = 2.75 hours
8 hours and 15 minutes (8:15) = 8 + (15 ÷ 60) = 8 + 0.25 = 8.25 hours

How to Convert Decimal Hours to Hours and Minutes

Converting from decimal hours back to hours:minutes format also follows a straightforward process:

Formula:

Hours = Integer part of the decimal value

Minutes = (Decimal part × 60) rounded to nearest whole number

Examples:

1.5 hours = 1 hour and (0.5 × 60) = 1 hour and 30 minutes (1:30)
2.75 hours = 2 hours and (0.75 × 60) = 2 hours and 45 minutes (2:45)
8.25 hours = 8 hours and (0.25 × 60) = 8 hours and 15 minutes (8:15)

Common Time Conversion Reference Chart

This table provides quick reference for common time conversions between hours:minutes and decimal hours:

Hours:Minutes	Decimal Hours	Hours:Minutes	Decimal Hours
0:05	0.08	2:45	2.75
0:10	0.17	3:00	3.00
0:15	0.25	3:15	3.25
0:20	0.33	3:30	3.50
0:30	0.50	3:45	3.75
0:45	0.75	4:00	4.00
1:00	1.00	6:00	6.00
1:15	1.25	7:30	7.50
1:30	1.50	8:00	8.00
1:45	1.75	8:30	8.50
2:00	2.00	12:00	12.00
2:15	2.25	24:00	24.00
2:30	2.50	40:00	40.00

Applications of Time Format Conversion

Time format conversion is essential in many professional and personal contexts:

Payroll and Timekeeping

Most payroll systems calculate wages based on decimal hours. For example, if an employee works from 9:00 AM to 5:30 PM (8.5 hours) at $20 per hour, their earnings would be 8.5 × $20 = $170.

Professional Billing

Lawyers, consultants, and other professionals often bill in increments like tenths or quarters of an hour. Converting time worked to the appropriate decimal format ensures accurate billing.

Project Management

When estimating project timelines or tracking hours spent on tasks, converting between time formats helps in calculating total effort and resource allocation.

Academic and Scientific Research

Researchers often need to convert time measurements for data analysis, particularly when calculating averages or performing statistical analysis on time-based data.

Time Conversion for Different Industries

Payroll and HR

In payroll processing, time is typically recorded in hours:minutes but calculated in decimal hours:

An employee working 7 hours and 45 minutes would be paid for 7.75 hours
For biweekly payroll, an employee working 80 hours and 30 minutes would be paid for 80.5 hours
Many timekeeping systems automatically convert clock-in/clock-out times to decimal hours

Legal and Professional Services

Attorneys and consultants typically bill in specific increments:

Some law firms bill in 6-minute increments (tenths of an hour): 0.1 = 6 min, 0.2 = 12 min, etc.
Others bill in 15-minute increments (quarters of an hour): 0.25 = 15 min, 0.5 = 30 min, etc.
A 50-minute consultation might be billed as 0.8 or 0.9 hours depending on the firm's billing policy

Construction and Contracting

Construction projects often require detailed time tracking:

Labor costs might be calculated based on decimal hours (e.g., 38.5 hours of carpentry work)
Equipment rental often uses decimal days or hours (e.g., a backhoe used for 4.25 hours)
Project timelines typically use decimal days to calculate completion dates and critical paths

Time Conversion Methods and Shortcuts

Common Minute Conversions

15 minutes = 0.25 hours (quarter hour)
30 minutes = 0.50 hours (half hour)
45 minutes = 0.75 hours (three-quarter hour)
10 minutes = 0.17 hours (one-sixth hour)
20 minutes = 0.33 hours (one-third hour)
40 minutes = 0.67 hours (two-thirds hour)
6 minutes = 0.10 hours (one-tenth hour)

Mental Math Shortcuts

For 1-minute increments: divide by 60 (e.g., 42 min = 42/60 = 0.7 hours)
For 5-minute increments: multiply by 5, then divide by 300 (e.g., 9 × 5 min = 45/60 = 0.75 hours)
For 15-minute increments: divide by 4 (e.g., 2 × 15 min = 30/60 = 0.5 hours)
For 30-minute increments: divide by 2 (e.g., 1 × 30 min = 0.5 hours)

Frequently Asked Questions About Time Conversion

How do I convert 1 hour and 45 minutes to decimal hours?

To convert 1:45 to decimal hours, take the whole hour (1) and add the minutes divided by 60: 1 + (45/60) = 1 + 0.75 = 1.75 hours. The formula is: Hours + (Minutes ÷ 60).

How do I convert 2.5 decimal hours to hours and minutes?

To convert 2.5 decimal hours to hours:minutes format, take the whole number (2) as the hours. Then multiply the decimal part (0.5) by 60 to get the minutes: 0.5 × 60 = 30 minutes. So 2.5 hours equals 2 hours and 30 minutes, or 2:30.

What is 0.25 hours in minutes?

To convert decimal hours to minutes, multiply the decimal hours by 60. So 0.25 hours × 60 = 15 minutes. Similarly, 0.5 hours = 30 minutes, and 0.75 hours = 45 minutes.

How do payroll systems handle time conversion?

Most payroll systems automatically convert hours:minutes format to decimal hours for wage calculations. For example, if an employee works 7:45 (7 hours and 45 minutes), the system would convert this to 7.75 hours before multiplying by the hourly rate. Some systems round to the nearest quarter hour or other increment based on company policy.

How do I calculate overtime using decimal hours?

To calculate overtime, first convert all working hours to decimal format. For example, if someone worked 42 hours and 30 minutes in a week, that would be 42.5 hours. If overtime starts after 40 hours and is paid at 1.5 times the normal rate, you would calculate: 40 hours at regular pay + 2.5 hours at overtime pay.

What's the difference between decimal hours and hours:minutes?

Hours:minutes (HH:MM) is a traditional time format that divides an hour into 60 equal parts (minutes). Decimal hours express time as a decimal number, where the fractional part represents a portion of an hour. For example, 2:30 (2 hours and 30 minutes) equals 2.5 decimal hours, since 30 minutes is half an hour.

How do I handle time that spans multiple days?

When converting time that spans multiple days, you can either: 1) Convert each day separately and then add the results, or 2) Calculate the total hours:minutes across all days and then convert to decimal. For example, 3 days, 4 hours, and 30 minutes could be expressed as 76.5 hours (3×24 + 4 + 0.5).

How precise should decimal time calculations be?

The level of precision depends on your specific needs. For payroll, decimal hours are typically rounded to the nearest hundredth (two decimal places). For scientific or technical calculations, you might need more precision. Most professional industries use two decimal places for billing and payroll purposes.

Hours and Minutes to Decimal Converter - Time Format Conversion Tool