Milliseconds to Seconds Converter

The formula is: seconds = milliseconds ÷ 1,000.

Worked example: 1,500 milliseconds is 1.5 seconds.

To go the other way, use the Seconds to Milliseconds Converter, which multiplies by 1,000 instead of dividing.

A millisecond is a unit of time equal to one thousandth (1/1,000) of a second. The prefix milli means one thousandth in the metric system, the same prefix used in millimeter and milliliter. Its symbol is ms, and it is also informally called a milli or millis, which is why many people search for millis to seconds.

The second itself is the SI base unit of time, defined by the International System of Units using a fixed frequency of the caesium 133 atom (9,192,631,770 oscillations per second). Because the millisecond is defined directly from the second, the 1,000 to 1 ratio is exact, with no rounding.

Smaller and Larger Units Around the Millisecond

Common values in milliseconds and their equivalents in seconds:

Programming is the biggest reason people convert milliseconds. JavaScript functions such as setTimeout and setInterval take their delay in milliseconds, so setTimeout(fn, 30000) waits 30 seconds, and Date.now() returns a Unix timestamp counted in milliseconds. Outside of code, milliseconds show up in monitor response times, audio latency and delay effects (one cycle of a 1 kHz tone lasts exactly 1 ms), camera shutter speeds, and sprint or racing results, where a gap of a few hundred milliseconds can decide a finish.

Avoiding the Integer Division Bug

In languages that divide whole numbers as integers (Java, C, C#, and others), 500 / 1000 evaluates to 0 instead of 0.5, so a millisecond value silently turns into zero seconds. Divide by 1000.0, or convert the value to a decimal type first, to keep the fraction. JavaScript and Python 3 divide as decimals by default, so 500 / 1000 returns 0.5 there.

Milliseconds also come up outside unit conversion: the BPM to Milliseconds Delay Calculator sets delay times from a song's tempo, and the Unix Timestamp Converter turns a Unix timestamp into a readable date.

Every time converter that shares a unit with this page, starting with the reverse conversion, one page per pair of units, then the converters that show many units at once.

• Seconds to Milliseconds Converter: 1 second = 1,000 milliseconds
• Seconds to Hours Converter: 1 hour = 3,600 seconds
• Minutes to Seconds Converter: 1 minute = 60 seconds
• Seconds to Days Converter: 1 day = 86,400 seconds
• Seconds to Years Converter: 1 year is 31,557,600 seconds on average
• Day Converter: days to hours, minutes, weeks, fortnights, months and years at once
• Hour Converter: hours to minutes, seconds, days, weeks, months and years at once
• Minute Converter: minutes to hours, seconds, days, weeks and more at once
• Seconds Converter: seconds to milliseconds, nanoseconds, minutes, hours and more at once
• Milliseconds Converter: milliseconds to seconds, minutes, microseconds and more at once
• Time Unit Converter: any amount of time in 13 units, from picoseconds to decades