Time Duration Calculator
Free online time duration calculator. Find the exact duration between two dates and times in years, months, days, hours, minutes, and seconds.
How to Use the Time Duration Calculator
Enter a start date and time and an end date and time. The calculator shows the exact duration broken down into years, months, days, hours, minutes, and seconds. If the end time is in the future, a live countdown is displayed.
About This Tool
Calculate the exact duration between two dates and times, broken down into every unit from years to seconds. Includes a live countdown timer when the end time is in the future, and a progress bar showing elapsed percentage. Useful for event countdowns, project timelines, and measuring elapsed time. Related: Date Calculator for date arithmetic, Days Between Dates for simple day counts.
Frequently Asked Questions
Does the countdown update in real time?
Yes. When the end date is in the future, a live countdown ticks every second showing the remaining time.
How accurate is the duration calculation?
It is accurate to the second. Months and years are calculated using calendar rules, accounting for varying month lengths and leap years.
Can I see the total in a single unit?
Yes. In addition to the full breakdown, the calculator shows total days, total hours, total minutes, and total seconds.