Weeks, Months & Years Between Dates
Calculate weeks between dates, months between dates, and years between two dates — all at once. Get both exact fractional results and complete unit breakdowns.
Weeks, Months & Years Between Dates
Calculate the difference in weeks, months, and years between two dates
What Does This Calculator Do?
This calculator answers all the multi-unit date difference questions at once: how many weeks between dates, how many complete months, and how many years — both as exact fractional numbers and as full-unit breakdowns. It's the most complete view of any date interval.
The exact breakdown (2 years, 3 months, 14 days) counts full completed calendar units. The fractional numbers (27.49 months, 119.57 weeks) use average lengths and are useful for prorated rent, interest calculations, subscription billing, or any scenario where partial units matter.
How to Calculate Weeks Between Dates
- 1Enter your start date in the first date field.
- 2Enter your end date in the second date field.
- 3Click "Calculate Weeks, Months & Years."
- 4The headline result shows the exact breakdown in years, months, and days.
- 5The detail row shows fractional weeks, months, years, and total days.
- 6Click "Copy" to grab all results as formatted text.
Weeks, Months, Years — Conversion Reference
Common Use Cases
Frequently Asked Questions
How do I calculate weeks between two dates?
Enter your start and end dates in the calculator above and click "Calculate Weeks, Months & Years." The result shows the exact number of weeks (as a decimal) and the count of full weeks, along with months and years.
How do I calculate months between two dates?
The calculator returns both the exact fractional months (e.g., 14.76 months) and the number of complete months. The exact figure is calculated as total days ÷ 30.436875 (the average month length).
How many weeks are in a year?
A standard year has exactly 52 weeks and 1 day (365 days ÷ 7 = 52.14 weeks). A leap year has 52 weeks and 2 days (366 ÷ 7 = 52.29 weeks). The calculator handles both automatically.
What is the difference between exact and approximate months/years?
The "exact" breakdown (e.g., "2 years 3 months 15 days") counts whole completed calendar units. The fractional numbers (e.g., "27.49 months") use average month/year lengths, which is more useful for prorated calculations.
How many months between two dates in different years?
The calculator computes the full breakdown: for example, from January 1, 2023 to September 15, 2025 is exactly 2 years, 8 months, and 14 days — or approximately 32.45 months. Enter any two dates to get the precise result.