Time Converter

About this Time Converter

The Time Converter changes duration values across seconds, minutes, hours, days and weeks. It is intended for duration arithmetic rather than timezone conversion or calendar date calculations.

Converting between time units like seconds, minutes, hours, days and weeks becomes error-prone once you're working across several units at once, which is why a direct converter is faster and more reliable than chaining multiple manual multiplications.

For related tasks, try Hours & Minutes to Decimal, Decimal Hours to Time or Time Duration Calculator.

How to use it

1. Enter the duration value.
2. Select the source duration unit.
3. Select the target unit and convert.

Practical example

48 hours equals 2 days, while one week equals 168 hours or 604,800 seconds.

2 weeks converts to exactly 336 hours, or 20,160 minutes, or 1,209,600 seconds, numbers that grow large quickly and are far more reliably calculated by a converter than estimated by hand.

Things to double-check

A calendar month and a calendar year are not fixed numbers of days, so this converter's day/week/hour conversions are exact, but any conversion involving months or years elsewhere is necessarily an approximation.

Time units and exact factors

A minute is 60 seconds, an hour is 3,600 seconds, a day is 86,400 seconds and a week is 10,080 minutes. So 90 minutes is 1.5 hours, 36 hours is 1.5 days and 10,000 seconds is 2 hours, 46 minutes and 40 seconds. These units are exact, unlike months and years, which have variable length. The converter handles the chain of multiplications that is easy to get wrong by hand.

Why months and years are not here

A month is 28 to 31 days and a year is 365 or 366 days, so there is no exact conversion in seconds or hours. For rough planning people use 30 days for a month and 365.25 for a year, which is about 31,557,600 seconds. If you need exact calendar differences, use the Date Difference Calculator, which works with real dates.

Project and work planning

Time conversion is useful for planning. A task of 2,500 minutes is about 41.7 hours, or roughly five working days of 8 hours. A deadline in 10 days is 240 hours, but only about 80 working hours if you work 8 hours on 10 weekdays. Convert carefully and separate calendar time from working time, and add buffer for meetings and interruptions.

Speed, sport and science

In sport, race times are converted between seconds and minutes, such as a 100 m in 9.58 seconds, or a marathon in 2 hours, 1 minute and 9 seconds, which is 7,269 seconds. Computing uses milliseconds and microseconds, and astronomers use much longer units. Using seconds as a common unit makes it easy to compare events. Convert to seconds, calculate, and convert the answer back.

Large time spans

Large numbers of seconds are hard to picture. One million seconds is about 11.6 days, and one billion seconds is about 31.7 years. A week has 168 hours and 604,800 seconds, and a 40 hour working week is about 24 percent of all the hours in a week. Converting to days or weeks helps you judge the scale of a number, whether it is the lifetime of a battery, the length of a process or a countdown in seconds.

Work and study hours in other units

Converting hours into other units gives a feel for large amounts of time. A 40 hour working week is 2,400 minutes or 144,000 seconds, and an 8 hour day is 28,800 seconds. A target of 1,000 hours of practice is about 41.7 full days if you did nothing else, or 25 weeks at 40 hours a week. The popular figure of 10,000 hours is about 416.7 days of non-stop work, or roughly 4.8 years of 40 hour weeks with no holidays. These conversions help you set realistic study and training plans.

Worked examples

A duration of 3 hours and 45 minutes is 225 minutes or 13,500 seconds. A project of 2.75 days is 66 hours. A countdown of 100,000 seconds is 27.8 hours, or 1 day, 3 hours, 46 minutes and 40 seconds. The easiest method is to convert everything to seconds, which is the base unit, add or compare, and then convert the answer back. Writing down the factors 60, 3,600 and 86,400 for minutes, hours and days in seconds makes the arithmetic dependable, and the calculator removes the chance of slips.

Time budgeting

Converting time is useful when you plan your week. There are 168 hours in a week. If you sleep 8 hours a night, that is 56 hours. A 40 hour working week and 5 hours of commuting leave 67 hours for meals, family, study, exercise and rest. Seeing the numbers helps you decide what to protect and what to drop, and it shows how much time a new commitment really takes. A task that needs 90 minutes three times a week costs 4.5 hours, which is more than a full evening, so plan for it in advance.

Working with durations in spreadsheets

Spreadsheets store times as fractions of a day, so 12 hours is 0.5. To add durations over 24 hours, use a format that shows total hours, not clock time, or the total will wrap around. To convert a duration to decimal hours, multiply by 24, and to minutes, multiply by 1,440. When you sum the time worked in a week, check that the total makes sense by converting it to hours and minutes manually for one day. This avoids common errors in timesheets and project plans.

How time is defined

The second is defined by the frequency of a transition in caesium-133 atoms, which completes 9,192,631,770 cycles in one second, and atomic clocks keep time with extraordinary precision. Clock time, called UTC, is occasionally adjusted with leap seconds to stay close to the rotation of the earth. Computers measure small intervals in milliseconds, microseconds and nanoseconds, and light travels about 30 centimetres in one nanosecond. Knowing these scales helps when you read technical specifications about response times and delays.

Key terms explained

A second is the SI unit of time. A minute is 60 seconds, an hour is 60 minutes and a day is 24 hours. A week is 7 days. A millisecond is a thousandth of a second, a microsecond a millionth and a nanosecond a billionth. A calendar month and a year vary in length, so they are not fixed multiples. Duration is the length of a period, and a timestamp marks a moment. UTC is the standard reference time.

Rules of thumb and quick checks

There are 60 seconds in a minute, 3,600 in an hour, 86,400 in a day and 604,800 in a week. Multiply hours by 60 to get minutes and by 3,600 to get seconds. A year of 365.25 days has about 31.56 million seconds. To convert minutes to a decimal fraction of an hour, divide by 60. For long periods use days, and use the Date Difference Calculator when calendar months matter.

Quick reference and sanity checks

These exact values cover most time conversions. One minute is 60 seconds, one hour is 3,600 seconds, one day is 86,400 seconds and one week is 604,800 seconds. A common year of 365 days is 31,536,000 seconds, and a leap year has one extra day. Months and years are not fixed lengths, so a converter has to use an average or a stated convention, such as 30 days for a month or 365 days for a year. If the answer matters for a contract or a schedule, use real calendar dates with the date difference calculator instead of an average, and write the convention you used beside the result.

Frequently asked questions