Date Difference Calculator
Difference = End Date − Start DateDec 31 − Jan 1 = 364 days (non-leap year)
Free online tool
Date Difference Calculator
Enter two dates to calculate the precise gap between them, including total days and weeks.
Instant calculation
Calculate Date Difference
Enter a start date and an end date to find the exact difference.
Your result
Calculation
Your numbers stay in this browser. Nothing is uploaded or saved.
Three clear steps
How to use this calculator
- 01
Enter the start date
Type the year, month and day for the earlier date.
- 02
Enter the end date
Type the year, month and day for the later date.
- 03
See the difference
Calculate to see the exact gap in years, months, days, weeks and total days.
The formula
How this calculation works
Count the full years between the dates, then the remaining months, then the days. Total days, weeks and months are also calculated.
Check the method
Worked examples
Each example follows the same formula used by the calculator.
Days between Jan 1 and Dec 31, 2026?
Dec 31 − Jan 1 = 364 days (non-leap year)364 daysYears between 1990 and 2026?
2026 − 1990 = 36 years36 yearsCommon questions
Questions about this calculation
How is the date difference calculated?
The calculator counts the full years between the two dates, then the remaining months, then the days. It also provides total days, weeks and months.
Can I calculate backwards from an earlier date?
Yes. The calculator works in both directions. If the end date is before the start date, the difference is still displayed correctly.
Does the date difference include the end date?
The calculation counts full calendar days between the two dates. The first day is exclusive and the last day is inclusive for a forward calculation.
What date format should I use?
Enter the year, month and day in separate fields. Month uses 1 for January through 12 for December.
Can I use this to calculate ages?
Yes. The Age Calculator is built on the same algorithm. For a direct age calculation, use the Age Calculator instead.
Continue calculating