⏳ Duration Converter
Convert between seconds, minutes, hours, days, weeks, months, and years in real time. Handy for quickly answering "how many days is that many hours?" or "how many minutes is that many seconds?"
How to use
- Enter a value into any duration unit field (seconds, minutes, hours, days, weeks, months, or years).
- The converted values appear instantly in the other unit fields.
How the calculation works
Everything is converted through seconds. A minute is 60 s, an hour 3,600 s, a day 86,400 s and a week 604,800 s — all exact by definition. Months and years are not fixed: months run from 28 to 31 days, and a year is 365 or 366 days. So this tool takes a year as 365.25 days (31,557,600 s), averaging in leap years, and a month as a twelfth of that, about 30.44 days. It is the same length as the Julian year used in astronomy. Because these are averages, results differ slightly from calendar arithmetic such as "three months from now". To count days from a specific date, use the date calculator instead.
Worked example
How many days is a million seconds? 1,000,000 ÷ 86,400 ≈ 11.57 days A billion seconds is 1,000,000,000 ÷ 31,557,600 ≈ 31.69 years. "A million seconds is about eleven and a half days; a billion is about 32 years" — one extra step of magnitude changes the picture completely. 1,000 hours is 1,000 ÷ 24 ≈ 41.67 days, about six weeks.
Things to be aware of
- Months and years are averages (year = 365.25 days, month ≈ 30.44 days) and may not match calendar days.
- Leap seconds are not accounted for.
- For the number of days between two specific dates, use the date calculator.
- The hours/minutes/seconds converter is handy for switching between clock notation and seconds.
FAQ
How are months and years calculated?
A month is treated as its average length (about 30.44 days), and a year as 365.25 days (an average that accounts for leap years). This can differ slightly from exact calendar counts.
Is this useful for precise second-level calculations?
Yes — it's handy for converting video runtimes or work durations given in seconds into minutes or hours.
Can this calculate the number of days between two specific dates?
This tool only converts between units. To count days between two specific dates, try our Date Calculator.