Free Online Days Calculator

Count days between dates or add/subtract days.

Select dates and click Calculate.

About the Days Calculator

This free online days calculator lets you quickly find the exact number of days between any two dates, including a breakdown of weeks, business days (weekdays), and weekend days. You can also switch to Add/Subtract mode to find a future or past date by adding or removing a specific number of days.


All calculations run entirely in your browser — fast, private, and accurate. It handles leap years, month boundaries, and timezone-independent date math.

How to Use

  1. Choose Mode: "Days Between" to count days, or "Add / Subtract" to find a target date.
  2. Enter Dates: Pick your start and end dates (or a date and number of days).
  3. Calculate: Click the button to see detailed results instantly.

Common Uses

  • Project Planning: Count business days between milestones.
  • Deadlines: Add days to today to find a due date.
  • Travel: Calculate trip duration in days.
  • Contracts: Count calendar or business days for notice periods.