Time Converter
Convert any duration between milliseconds, seconds, minutes, hours, days, weeks, months and years, with every unit calculated at once. Month and year use calendar averages.
Time Converter
Time — Result
0.001 s
1 Millisecond = 0.001 Second
How It Works
Time converters use the second (the SI base unit of time) as the anchor and assign each unit a factor: 1 minute = 60 s, 1 hour = 3,600 s, 1 day = 86,400 s, and 1 week = 604,800 s. Months and years are trickier because calendar months vary from 28 to 31 days and years include leap years. This converter uses averages: an average month of 30.44 days (2,629,800 s) and an average Gregorian year of 365.25 days (31,557,600 s), which is the standard approach for duration arithmetic. For exact calendar differences between two specific dates — accounting for real month lengths and leap years — use a Date Difference or Age calculator instead, which count actual days rather than using averages.
Formula
Result = value × (seconds per from-unit) ÷ (seconds per to-unit). Base: second. 1 min = 60 s, 1 h = 3600 s, 1 day = 86,400 s. Month/year use averages.
Frequently Asked Questions
How many seconds are in a day?
A day has 86,400 seconds: 24 hours × 60 minutes × 60 seconds. A week has 604,800 seconds (7 × 86,400).
Why is a month shown as 30.44 days?
Calendar months range from 28 to 31 days, so for converting a duration in months to other units, an average is used: 365.25 ÷ 12 ≈ 30.44 days. For exact date-to-date gaps, use a Date Difference calculator instead.
How many hours are in a year?
Using an average year of 365.25 days: 365.25 × 24 = 8,766 hours. A common (non-leap) 365-day year has 8,760 hours.
What is the difference between a duration and a date difference?
A duration converts a fixed span (e.g., 90 minutes → 1.5 hours) using constant factors. A date difference counts the exact days between two calendar dates, including real month lengths and leap years — which averages can’t capture.
How do I convert minutes to hours?
Divide minutes by 60. For example, 150 minutes = 150 ÷ 60 = 2.5 hours. To convert hours to minutes, multiply by 60.