Time Converter

Enter a value to instantly convert between time units.

Time conversions are some of the most universally familiar — everyone has converted hours to minutes or days to weeks — but they're also needed for more specialized tasks like calculating project durations in working days, converting scientific measurements involving milliseconds or microseconds, or figuring out exactly how many days are in a given number of years for age or interest calculations. Unlike most categories on this site, time units don't follow a single consistent base (some units are powers of 10 apart, others — like hours to days — are not), which is a quirk worth understanding.

From

Precision4 dp

1 Hour = 60 Minute

Key Formulas

Hour → Minute

min = h × 60

Minute → Hour

h = min × 0.0166667

Day → Hour

h = d × 24

Hour → Day

d = h × 0.0416667

Popular Conversions

Minute to Hour Hour to Minute Hour to Day Day to Hour Week to Day Year (avg) to Day

All Time Conversions

Minute to Hour Hour to Minute Hour to Day Day to Hour Week to Day Year (avg) to Day Second to Millisecond Second to Microsecond Second to Nanosecond Second to Minute Second to Hour Second to Day Second to Week Second to Month (avg) Second to Year (avg) Second to Decade Second to Century Millisecond to Second Millisecond to Microsecond Millisecond to Nanosecond Millisecond to Minute Millisecond to Hour Millisecond to Day Millisecond to Week Millisecond to Month (avg) Millisecond to Year (avg) Millisecond to Decade Millisecond to Century Microsecond to Second Microsecond to Millisecond Microsecond to Nanosecond Microsecond to Minute Microsecond to Hour Microsecond to Day Microsecond to Week Microsecond to Month (avg) Microsecond to Year (avg) Microsecond to Decade Microsecond to Century Nanosecond to Second Nanosecond to Millisecond Nanosecond to Microsecond Nanosecond to Minute Nanosecond to Hour Nanosecond to Day Nanosecond to Week Nanosecond to Month (avg) Nanosecond to Year (avg) Nanosecond to Decade Nanosecond to Century Minute to Second Minute to Millisecond Minute to Microsecond Minute to Nanosecond Minute to Day Minute to Week Minute to Month (avg) Minute to Year (avg) Minute to Decade Minute to Century Hour to Second Hour to Millisecond Hour to Microsecond Hour to Nanosecond Hour to Week Hour to Month (avg) Hour to Year (avg) Hour to Decade Hour to Century Day to Second Day to Millisecond Day to Microsecond Day to Nanosecond Day to Minute Day to Week Day to Month (avg) Day to Year (avg) Day to Decade Day to Century Week to Second Week to Millisecond Week to Microsecond Week to Nanosecond Week to Minute Week to Hour Week to Month (avg) Week to Year (avg) Week to Decade Week to Century Month (avg) to Second Month (avg) to Millisecond Month (avg) to Microsecond Month (avg) to Nanosecond Month (avg) to Minute Month (avg) to Hour Month (avg) to Day Month (avg) to Week Month (avg) to Year (avg) Month (avg) to Decade Month (avg) to Century Year (avg) to Second Year (avg) to Millisecond Year (avg) to Microsecond Year (avg) to Nanosecond Year (avg) to Minute Year (avg) to Hour Year (avg) to Week Year (avg) to Month (avg) Year (avg) to Decade Year (avg) to Century Decade to Second Decade to Millisecond Decade to Microsecond Decade to Nanosecond Decade to Minute Decade to Hour Decade to Day Decade to Week Decade to Month (avg) Decade to Year (avg) Decade to Century Century to Second Century to Millisecond Century to Microsecond Century to Nanosecond Century to Minute Century to Hour Century to Day Century to Week Century to Month (avg) Century to Year (avg) Century to Decade

About Time Conversions

History & Background

The division of the day into 24 hours and the hour into 60 minutes traces back to ancient Babylonian and Egyptian astronomy, which used a base-60 (sexagesimal) numbering system — a convention so deeply embedded that it has survived essentially unchanged for thousands of years, unlike almost every other measurement system, which has been metricated. The second, now the SI base unit of time, was originally defined as a fraction of the day (1/86,400) but has since been redefined in terms of atomic clock oscillations for extreme precision — a definition completely decoupled from its historical origin as 'a small fraction of a day,' even though the numerical relationship (86,400 seconds per day) remains unchanged for everyday purposes.

How to Use This Converter

Select your starting and target time units and enter a value for an instant conversion. Because units like years contain a fractional number of days (365.25, accounting for leap years), conversions involving years use an averaged value — for precise date-based calculations (e.g., 'exactly how many days between these two dates'), a calendar-based calculation rather than a unit conversion is more appropriate.

Frequently Asked Questions

Why does a year not convert to a round number of days?

A calendar year is approximately 365.25 days (which is why a leap day is added roughly every 4 years) — so any conversion involving years uses this averaged figure rather than exactly 365, to remain accurate over long periods. For a specific calendar year, the actual number of days is either 365 or 366 depending on whether it's a leap year.

What are milliseconds, microseconds, and nanoseconds used for?

These very small time units are common in computing, electronics, and physics — a computer processor might execute an instruction in nanoseconds, while network latency is often measured in milliseconds. They follow the standard metric prefix pattern (milli = 1/1,000, micro = 1/1,000,000, nano = 1/1,000,000,000 of a second), unlike the hour/day/week/year relationships, which don't follow powers of 10.

How many seconds are in a day, and why does that number matter?

There are 86,400 seconds in a day (24 × 60 × 60). This number appears throughout science and computing — for example, it's the basis for converting between data transfer rates measured per second and totals measured per day, and it's a useful figure to have memorized for quick estimates involving daily totals.

Popular Use Cases

These conversions are also featured in:

Fitness Converter Science & Lab Converter