Hours and Minutes Calculator

Decimal time represents hours as a single decimal number where the fractional part represents a fraction of an hour, not minutes. This distinction is critical: 7.50 hours means 7 hours and 30 minutes (not 7 hours 50 minutes), because 0.50 of 60 minutes equals 30 minutes. The conversion from decimal to hours and minutes uses the floor function for the whole hours and multiplies the fractional remainder by 60 for the minutes. Going the other direction, hours and minutes convert to decimal by dividing the minutes by 60 and adding to the hours. Common decimal-to-minutes conversions include: 0.10 = 6 min, 0.25 = 15 min, 0.33 = 20 min, 0.50 = 30 min, 0.67 = 40 min, 0.75 = 45 min, and 0.83 = 50 min. Memorizing these speeds up mental conversions. Decimal time is preferred in payroll because it simplifies multiplication. If an employee works 7.75 hours at $20/hour, the pay is simply 7.75 * 20 = $155. Using hours and minutes (7:45) would require converting first. The French revolutionary decimal time system, introduced in 1793, divided the day into 10 hours of 100 minutes each. While more mathematically elegant, it was abandoned after just 17 months because the existing sexagesimal system was too deeply embedded in society and technology.