Time Converter

Months and years use average lengths (365.25 days/yr).

Quick Reference

1 minute  = 60 seconds
1 hour    = 60 minutes   = 3,600 seconds
1 day     = 24 hours    = 86,400 seconds
1 week    = 7 days      = 604,800 seconds
1 month*  = 30.4375 days  = 2,629,800 seconds
1 year*   = 365.25 days  = 31,557,600 seconds
* average values

Common Conversions

  • 1 billion milliseconds ≈ 11.57 days
  • 1 million seconds ≈ 11.57 days
  • 1 billion seconds ≈ 31.7 years
  • A 40-hour work week = 2,400 minutes = 144,000 seconds
  • The average human lifespan (79 years) ≈ 2.49 billion seconds

Frequently Asked Questions

How many seconds in a day?

There are exactly 86,400 seconds in one day: 24 hours × 60 minutes × 60 seconds.

How many seconds in a year?

A common year has 31,536,000 seconds (365 × 86,400). A leap year has 31,622,400. This converter uses 31,557,600 (365.25 × 86,400) to account for leap years on average.

Why are months and years approximate?

Calendar months range from 28 to 31 days and years are either 365 or 366 days. This converter uses average values (365.25 days/year, 30.4375 days/month) for consistent results. For exact calculations involving specific dates, use the Date Calculator.

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