Time Converter

Convert between all common time units including seconds, milliseconds, minutes, hours, days, weeks, months, years, decades, and centuries.

Time Converter 12 units

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Common Time Conversions

All Time Conversions

Browse all unit combinations — each page has a dedicated converter and conversion table.

Seconds → Milliseconds Seconds → Microseconds Seconds → Nanoseconds Seconds → Minutes Seconds → Hours Seconds → Days Seconds → Weeks Seconds → Months Seconds → Years Seconds → Decades Seconds → Centuries Milliseconds → Seconds Milliseconds → Microseconds Milliseconds → Nanoseconds Milliseconds → Minutes Milliseconds → Hours Milliseconds → Days Milliseconds → Weeks Milliseconds → Months Milliseconds → Years Milliseconds → Decades Milliseconds → Centuries Microseconds → Seconds Microseconds → Milliseconds Microseconds → Nanoseconds Microseconds → Minutes Microseconds → Hours Microseconds → Days Microseconds → Weeks Microseconds → Months Microseconds → Years Microseconds → Decades Microseconds → Centuries Nanoseconds → Seconds Nanoseconds → Milliseconds Nanoseconds → Microseconds Nanoseconds → Minutes Nanoseconds → Hours Nanoseconds → Days Nanoseconds → Weeks Nanoseconds → Months Nanoseconds → Years Nanoseconds → Decades Nanoseconds → Centuries Minutes → Seconds Minutes → Milliseconds Minutes → Microseconds Minutes → Nanoseconds Minutes → Hours Minutes → Days Minutes → Weeks Minutes → Months Minutes → Years Minutes → Decades Minutes → Centuries Hours → Seconds Hours → Milliseconds Hours → Microseconds Hours → Nanoseconds Hours → Minutes Hours → Days Hours → Weeks Hours → Months Hours → Years Hours → Decades Hours → Centuries Days → Seconds Days → Milliseconds Days → Microseconds Days → Nanoseconds Days → Minutes Days → Hours Days → Weeks Days → Months Days → Years Days → Decades Days → Centuries Weeks → Seconds Weeks → Milliseconds Weeks → Microseconds Weeks → Nanoseconds Weeks → Minutes Weeks → Hours Weeks → Days Weeks → Months Weeks → Years Weeks → Decades Weeks → Centuries Months → Seconds Months → Milliseconds Months → Microseconds Months → Nanoseconds Months → Minutes Months → Hours Months → Days Months → Weeks Months → Years Months → Decades Months → Centuries Years → Seconds Years → Milliseconds Years → Microseconds Years → Nanoseconds Years → Minutes Years → Hours Years → Days Years → Weeks Years → Months Years → Decades Years → Centuries Decades → Seconds Decades → Milliseconds Decades → Microseconds Decades → Nanoseconds Decades → Minutes Decades → Hours Decades → Days Decades → Weeks Decades → Months Decades → Years Decades → Centuries Centuries → Seconds Centuries → Milliseconds Centuries → Microseconds Centuries → Nanoseconds Centuries → Minutes Centuries → Hours Centuries → Days Centuries → Weeks Centuries → Months Centuries → Years Centuries → Decades

📐 How to Use

Choose the unit of your duration in the From dropdown, from Nanosecond up to Century, and type the quantity underneath.
Choose the unit you want it expressed in using the To dropdown; the converted duration appears straight away in the result panel.
Use the swap button between the columns to turn the conversion around, for example hours to minutes into minutes to hours.
Press Copy for the converted value, pick a card from the Common Time Conversions grid, or open an entry in the All Time Conversions list for its own page and conversion table.

❓ Frequently Asked Questions

QHow many nanoseconds are in a century?

A century here is 3.15576e18 nanoseconds, since it holds 3,155,760,000 seconds and each second is a billion nanoseconds. The number is large enough that the display switches to scientific notation. That century is 100 Julian years of 365.25 days, not a leap-day count.

QHow many seconds are in an hour?

An hour is 3,600 seconds, a day is 86,400 and a week is 604,800. These follow from 60 seconds to the minute and 60 minutes to the hour, a sexagesimal habit inherited from Babylonian astronomy. Every unit up to the week is exact, with nothing averaged.

QHow long is a year in this converter?

A year is 365.25 days, or 31,557,600 seconds, which is the Julian year normally used for unit conversion. A decade is ten of those and a century 100. Gregorian calendar years average slightly less, at 365.2425 days, so treat long spans as approximations.

QWhy are month conversions only approximate?

Because no month has a fixed length. February has 28 or 29 days and the rest 30 or 31, so any single factor is an average, here 30.4375 days. For deadlines, count real calendar days; for estimates such as runtime per month, the average is fine.

ℹ️ About Time Conversion

Time seems like the one quantity nobody argues about, and up to the day it is: 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, all exact. Above the week the units stop being fixed. A calendar month runs 28 to 31 days and a year is 365 or 366, so every converter adopts an average. This one uses the Julian year of 365.25 days, making a month exactly one twelfth of that, 30.4375 days, and a century 100 such years.

Twelve units are listed, from nanoseconds to centuries. The second is the base: a value is multiplied by its unit's length in seconds and divided by that of the unit requested. Once a result passes a trillion, as nanoseconds in a century do, it is shown in scientific notation; ordinary results keep four to eight decimals. Everything is worked out in your browser.

📏 12 Supported Units

Second (s), Millisecond (ms), Microsecond (µs), Nanosecond (ns), Minute (min), Hour (hr), Day (d), Week (wk), Month (mo), Year (yr), Decade (dec), Century (c).