Time
sec, min, hr, days, years
About This Calculator
Time unit conversion translates between seconds, minutes, hours, days, weeks, months, and years. While most conversions are straightforward, months and years are approximate (they vary in length). These conversions are essential for unit analysis in science, calculating durations, and understanding orders of magnitude in time.
Formula
1 minute = 60 seconds
1 hour = 60 minutes = 3,600 seconds
1 day = 24 hours = 86,400 seconds
1 year = 365.25 days = 31,557,600 seconds (Julian year, used in astronomy)
Example Calculation
Convert 2.5 hours to seconds and minutes.
- Minutes = 2.5 × 60 = 150 minutes
- Seconds = 2.5 × 3,600 = 9,000 seconds
2.5 hours = 150 minutes = 9,000 seconds
Time Unit Conversions
| Unit | Seconds | Minutes | Hours | Days |
|---|---|---|---|---|
| 1 minute | 60 | 1 | 0.01667 | 0.000694 |
| 1 hour | 3,600 | 60 | 1 | 0.04167 |
| 1 day | 86,400 | 1,440 | 24 | 1 |
| 1 week | 604,800 | 10,080 | 168 | 7 |
| 1 month (avg) | 2,629,800 | 43,830 | 730.5 | 30.44 |
| 1 year (365 days) | 31,536,000 | 525,600 | 8,760 | 365 |
| 1 year (Julian) | 31,557,600 | 525,960 | 8,766 | 365.25 |
Frequently Asked Questions
How many seconds are in a year?
A common year (365 days) has 31,536,000 seconds. A leap year (366 days) has 31,622,400 seconds. The Julian year used in astronomy is 365.25 days = 31,557,600 seconds. The approximate value 3.15×10⁷ seconds/year is handy for quick calculations.
What is the difference between a Julian year and a calendar year?
A calendar year is either 365 or 366 days. A Julian year is exactly 365.25 days (accounting for the average leap year cycle). Astronomers use the Julian year for distances (light-year) and rates (parsec/year). For most conversions, 365 days is sufficient.
How many months is 90 days?
Approximately 2.96 months (90 / 30.44). Since months vary from 28-31 days, 90 calendar days may span 2-3 months depending on which months they fall in. For precision, count actual months rather than dividing by 30.
What is a fortnight?
A fortnight is 14 days (2 weeks). The term comes from Old English 'fourteen nights' and is commonly used in the UK and Australia for bi-weekly pay periods, rental agreements, and scheduling. In the US, 'biweekly' is more common.