Time and Duration Converter

Chronometry & The SI Base Unit of Time

The second (s) is the primary SI base unit of time, defined scientifically by measuring 9,192,631,770 periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom at 0 K.

Calendar Standards & Leap Cycles

• Standard Common Year: 365 days = 8,760 hours = 31,536,000 seconds.

• Leap Year: 366 days = 8,784 hours = 31,622,400 seconds (adds February 29).

• Gregorian Year Average: 365.2425 days (accounting for leap years every 4 years, omitting century years not divisible by 400).

• Julian Astronomical Year: Exactly 365.25 days (31,557,600 seconds), used in astronomy to compute light-year distances.

How to Use This Calculator

Enter your Time / Duration Value (e.g. 86400), From Unit — choose from Nanoseconds (ns), Microseconds (µs), Milliseconds (ms), and To Primary Target Unit — choose from Seconds (s), Minutes (min), Hours (hr). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Universal time and chronometric conversion standards:1 Minute = 60 Seconds1 Hour = 60 Minutes = 3,600 Seconds1 Day = 24 Hours = 1,440 Minutes = 86,400 Seconds1 Week = 7 Days = 168 Hours = 604,800 Seconds1 Gregorian Year = 365.2425 Days = 8,765.82 Hours = 31,556,952 Seconds

Worked Example

For example, converting 86,400 seconds: which equals exactly 1 Day 0h 0m 0s, 1,440.0 Minutes, and 0.002738 Years.

Understanding Your Result

Unit conversion precision: round to the same number of significant figures as your original measurement. Converting 6 feet to meters gives 1.8288 m — but if your measurement was approximate (±1 inch), expressing more than 2 decimal places is false precision. For international trade and technical specifications, SI units (meters, kilograms, liters) are the standard. US customary units (feet, pounds, gallons) differ from Imperial UK units: 1 US gallon = 3.785 L vs. 1 UK gallon = 4.546 L.