Time

What is a Hour?

The hour equals 3,600 seconds and structures workdays, broadcasts, and travel schedules around the world.

Overview

The hour equals exactly 3,600 seconds (60 minutes) and is the fundamental unit organizing human days, work schedules, broadcasts, and travel. The 24-hour day is rooted in ancient Egyptian astronomy, which divided the day and night into 12 segments each (originally variable in length depending on season, but standardized to 1/24 of a solar day in the Hellenistic period). Modern civilian and international time systems use the hour as the primary calendar division. Workdays are typically 8 hours, sleep cycles span 7–9 hours, and television programming is built around half-hour and one-hour blocks. The hour relates to the second (3,600 s = 1 h), the minute (60 min = 1 h), and the day (24 h = 1 day). Speed limits in km/h or mph and electricity prices in kWh ($/kWh) embed the hour as the time reference.

Symbol
h
Category
Time
Plural
hours

Convert Hour to all units

Live result
h
Second3,600 sMillisecond3,600,000 msMinute60 minDay0.041667 dWeek0.005952 wkMonth0.001369 moYear0.000114 yrDecade0.00001141 decCentury0.000001141 c

Relationship to Other Time Units

1 h equals

Visual reference for how the hour relates to other time units. Each row links to the full converter for that pair.

1 h=3,600 s1 h=3,600,000 ms1 h=60 min1 h=0.041667 d1 h=0.005952 wk1 h=0.001369 mo1 h=0.000114 yr1 h=0.00001141 dec1 h=0.000001141 c

When Is the Hour Used?

  • Work schedules and billing (hourly wage)
  • Flight and travel durations
  • Consumer-electronic battery life (in hours)
Real-world examples

Paris to Tokyo direct flight: 12 h. UK full-time standard: 37.5 h/week. Phone battery life: 8–20 h typical.

Tips for Using the Hour

  • 1 h = 60 min = 3600 s.
  • The official SI symbol is h.
  • 24 h in a day. Use 24-hour time (e.g. 14:30) for unambiguous clarity.

Common Mistakes

  • Writing "hr" in scientific contexts — the SI symbol is h.
  • Confusing 12-hour AM/PM with 24-hour time — always check.
  • Estimating travel times without rest and connections — real door-to-door is usually 30–50% longer.

Convert Hour to Other Time Units

Hour to Second
1 h = 3,600 s
Hour to Millisecond
1 h = 3,600,000 ms
Hour to Minute
1 h = 60 min
Hour to Day
1 h = 0.041667 d
Hour to Week
1 h = 0.005952 wk
Hour to Month
1 h = 0.001369 mo
Hour to Year
1 h = 0.000114 yr
Hour to Decade
1 h = 0.00001141 dec
Hour to Century
1 h = 0.000001141 c

Convert Other Units to Hour

Second to Hour
1 s = 0.000278 h
Millisecond to Hour
1 ms = 2.778e-7 h
Minute to Hour
1 min = 0.016667 h
Day to Hour
1 d = 24 h
Week to Hour
1 wk = 168 h
Month to Hour
1 mo = 730.485 h
Year to Hour
1 yr = 8,766 h
Decade to Hour
1 dec = 87,660 h
Century to Hour
1 c = 876,600 h

FAQ About the Hour

3 questions
What does the Hour (h) measure?
The hour measures time. The hour equals 3,600 seconds and structures workdays, broadcasts, and travel schedules around the world.
When is the Hour used?
The hour is used in: Work schedules and billing (hourly wage); Flight and travel durations; Consumer-electronic battery life (in hours). Paris to Tokyo direct flight: 12 h. UK full-time standard: 37.5 h/week. Phone battery life: 8–20 h typical.
How accurate are conversions involving the Hour?
All conversions on Units Converter use NIST SP 811 and BIPM reference values, accurate to 8 significant figures.