Time Converter
Convert between seconds, minutes, hours, days, weeks, months, years, decades, and centuries instantly.
How to use the time converter
Enter your time value in the "From Value" field and select the appropriate time unit from the dropdown menu. Choose your target unit in the "To Value" section, and the converted result will appear instantly. Use the swap button to quickly reverse the conversion direction. All calculations happen in your browser for complete privacy and instant results.
This converter handles everything from nanoseconds to centuries, making it perfect for scientific calculations, project planning, cooking timing, or everyday time conversions. The tool uses precise conversion factors based on international standards to ensure accuracy.
Understanding time conversions
Base time units
The second is the SI base unit for time, defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom. All other time units are derived from this fundamental definition established by the International Bureau of Weights and Measures (BIPM).
Common time relationships
60 seconds = 1 minute, 60 minutes = 1 hour, 24 hours = 1 day. These relationships originated from ancient Babylonian mathematics, which used a base-60 numeral system. This system has persisted for thousands of years and remains the global standard for timekeeping.
Calendar-based units
Months and years vary in length due to the Earth's orbit around the sun. Our converter uses average values: 30.44 days per month and 365.24 days per year. For precise calculations involving specific dates, consider using exact calendar dates rather than these average conversions.
Scientific time units
Milliseconds (1/1000 second), microseconds (1/1,000,000 second), and nanoseconds (1/1,000,000,000 second) are essential in computing, physics, and engineering. These units help measure processes that occur too quickly for human perception, such as computer processor cycles or chemical reactions.
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Frequently Asked Questions
How many seconds are in a day?
There are exactly 86,400 seconds in a day (24 hours × 60 minutes × 60 seconds). This conversion is fundamental for time calculations and programming.
How many weeks are in a year?
There are approximately 52.143 weeks in a year (365 days ÷ 7). A leap year has 52.286 weeks (366 days ÷ 7). This is useful for planning and scheduling.
How many minutes are in an hour?
There are exactly 60 minutes in an hour. This is based on the ancient Babylonian base-60 numeral system and has been standardized worldwide.
How do I convert months to weeks?
One month equals approximately 4.345 weeks (30.44 days ÷ 7). This uses the average month length. For specific months, use their actual days divided by 7.
How many milliseconds are in a second?
There are exactly 1,000 milliseconds in one second. This conversion is essential for programming, performance measurement, and scientific timing applications.