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Accurately convert between years, weeks, days, hours, minutes, seconds, milliseconds, microseconds, and nanoseconds with custom decimal precision.
Circle Area Calculator
Quickly calculate the area of a circle by entering the radius, diameter, or circumference. Supports custom units and precision settings.
Prime and Composite Number Calculator
Instantly identify prime, composite, or special numbers. Supports batch checking and mathematical property analysis.
Inverse Trigonometric Function Calculator
Accurately calculate radian values for inverse trig functions like arcsin and arccos. Supports 6 function types and custom decimal precision.
Trigonometry Calculator
Calculate six trigonometric functions from radian values with custom decimal precision.
Circle Area Calculator
Quickly calculate the area of a circle by entering the radius, diameter, or circumference. Supports custom units and precision settings.
Prime and Composite Number Calculator
Instantly identify prime, composite, or special numbers. Supports batch checking and mathematical property analysis.
Inverse Trigonometric Function Calculator
Accurately calculate radian values for inverse trig functions like arcsin and arccos. Supports 6 function types and custom decimal precision.
Trigonometry Calculator
Calculate six trigonometric functions from radian values with custom decimal precision.
Least Common Multiple (LCM) Calculator
Quickly calculate the least common multiple (LCM) of two or more integers. Supports space-separated number list input.
When you need to convert project hours into man-days, or change microsecond results in scientific calculations into more readable milliseconds, manual calculation is both tedious and prone to errors. This tool instantly performs accurate two-way conversions between nine common time units. Simply enter a value and select its unit to instantly get the equivalent value in all other units with one click. The core of time unit conversion lies in understanding the "second" (s) as the base unit of time in the International System of Units (SI). Other units like minutes, hours, and days are all defined and converted based on the second.
Q: Is a year calculated as 365 days or 365.25 days?
This tool defaults to 365.25 days as the standard value for 1 year. This accounts for leap years on average in long-term calculations, making the conversion between years and days more aligned with the actual average length of the Gregorian calendar.
Q: How do you calculate "how many milliseconds are in 1 hour"?
1 hour equals 3,600,000 milliseconds. Since 1 hour = 3,600 seconds and 1 second = 1,000 milliseconds, 3,600 * 1,000 = 3,600,000 milliseconds. You can directly enter "1" and select the unit "Hours" to verify this result.
The input value should be a pure number, supporting both integers and decimals. For extremely large or small values, there may be minuscule rounding errors due to the nature of computer floating-point arithmetic. The "year" in this tool uses the average astronomical year (Julian year) of 365.25 days, which is suitable for general scientific calculations. If used in strict financial or legal scenarios, please perform secondary calibration based on specific regulations (such as 365 or 360 days). All calculations are performed locally in your browser, and your input data is never uploaded to our servers.
For developers and engineers, understanding the base relationships of time units is crucial. Besides the common 60 seconds = 1 minute and 60 minutes = 1 hour, smaller units use a base-1000 system: 1 second (s) = 1,000 milliseconds (ms), 1 millisecond = 1,000 microseconds (µs), and 1 microsecond = 1,000 nanoseconds (ns). A typical use case is in performance optimization: if a piece of code takes 1,500 microseconds (µs) to execute, using this tool quickly reveals that this is equivalent to 1.5 milliseconds (ms) or 0.0015 seconds (s), facilitating more intuitive performance evaluation and reporting. When processing time data across multiple orders of magnitude, it is recommended to first convert all values to the same base unit (such as seconds or milliseconds) before performing calculations to avoid errors caused by unit confusion.
