Time Unit Converter — Seconds, Minutes, Hours, Days and Weeks
- 1 hour = 3,600 seconds = 60 minutes. 1 day = 86,400 seconds = 24 hours. This converter handles any time unit from milliseconds to years.
Table of Contents
1 hour = 3,600 seconds. 1 day = 86,400 seconds. Select the Time tab in the converter above to convert between milliseconds, seconds, minutes, hours, days, weeks, months, and years.
Time conversions come up in programming (milliseconds to seconds), project planning (hours to days), cooking (minutes to hours), and science (converting between any units of duration). Here is the complete reference.
Time Unit Conversion Table
| Unit | In Seconds | In Minutes | In Hours |
|---|---|---|---|
| 1 millisecond | 0.001 s | 0.0000167 min | 0.000000278 hr |
| 1 second | 1 s | 0.0167 min | 0.000278 hr |
| 1 minute | 60 s | 1 min | 0.0167 hr |
| 1 hour | 3,600 s | 60 min | 1 hr |
| 1 day | 86,400 s | 1,440 min | 24 hr |
| 1 week | 604,800 s | 10,080 min | 168 hr |
| 1 month (avg) | 2,629,746 s | 43,829 min | 730.5 hr |
| 1 year | 31,556,952 s | 525,949 min | 8,766 hr |
Common Time Conversions for Programming
Developers frequently need to convert between time units for timeouts, delays, and scheduled tasks:
- 1 second = 1,000 milliseconds
- 1 minute = 60,000 ms
- 30 minutes = 1,800,000 ms
- 1 hour = 3,600,000 ms
- 24 hours = 86,400,000 ms
JWT token expiry, cache TTL, rate limiting windows, and session durations are all commonly expressed in seconds or milliseconds.
Sell Custom Apparel — We Handle Printing & Free ShippingHow Many Seconds in a Day, Week, Year?
- 1 day: 86,400 seconds (24 × 60 × 60)
- 1 week: 604,800 seconds (7 × 86,400)
- 1 year: 31,536,000 seconds (365 days), or 31,557,600 seconds for an average year including leap years
- 1 decade: approximately 315,576,000 seconds
Hours and Minutes to Decimal Hours
Timesheet and billing calculations often need hours as a decimal. Divide minutes by 60 and add to hours: 7 hours 30 minutes = 7 + (30/60) = 7.5 decimal hours. 1 hour 45 minutes = 1.75 hours.
The converter handles time duration conversions — for clock arithmetic (adding times of day), you would need a different calculator.
Convert Time Units Free
Milliseconds to years — all time conversions in one free tool. No account needed.
Open Unit Converter FreeFrequently Asked Questions
How many seconds are in a day?
1 day = 24 hours × 60 minutes × 60 seconds = 86,400 seconds.
How many minutes in a year?
A standard 365-day year has 525,600 minutes. A leap year has 527,040 minutes.
How many milliseconds in a second?
1 second = 1,000 milliseconds. 1 millisecond = 0.001 seconds.
How many hours in a week?
1 week = 7 days × 24 hours = 168 hours.
