›› Measurement unit: hour

Full name: hour

Plural form: hours

Symbol: hr

Alternate spelling: hrs

Category type: time

Scale factor: 3600


›› SI unit: second

The SI base unit for time is the second.
1 second is equal to 0.00027777777777778 hour.


›› Convert hour to another unit

Convert hour to  

Valid units must be of the time type.
You can use this form to select from known units:

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›› Definition: Hour

The hour was originally defined in Egypt as 1/24 of a day, based on their duo-decimal numbering system (which counted finger joints on each hand).


›› Sample conversions: hour

hour to sidereal month
hour to Gregorian year
hour to century
hour to microsecond
hour to quarter
hour to lunar year
hour to synodic month
hour to Julian month
hour to draconic month
hour to fortnight