Count hotel nights between check-in and check-out dates, find a check-out date from a number of nights, and add a nightly rate to get the room cost.

Nights are counted up to, not including, the check-out date. A same-day stay counts as 0 nights.

Room cost
Optional. Shows the room cost for the stay before taxes and fees.

Related Calculators

Hotel Days Formula

The following formula is used to calculate the number of hotel days between two dates.

D = (Cout – Cin) / 86{,}400{,}000

Variables:

  • D is the number of hotel nights, excluding the check-out date
  • Cout is the check-out date represented at a fixed UTC reference time, in milliseconds since January 1, 1970
  • Cin is the check-in date represented at the same UTC reference time, in milliseconds since January 1, 1970

To calculate hotel nights, subtract the check-in calendar date from the check-out calendar date. When using millisecond timestamps, use the same UTC reference time for both dates and divide the difference by 86,400,000. The check-out date is excluded; equal dates give zero nights.

What is a Hotel Day?

A hotel day refers to the duration of stay at a hotel, typically calculated from the check-in date to the check-out date. It is a measure of the number of nights a guest stays at the hotel. This calculation is essential for determining the total cost of the stay, as hotels usually charge on a per-night basis. Understanding the number of hotel days helps both the guest and the hotel manage bookings, availability, and billing accurately.

How to Calculate Hotel Days?

The following steps outline how to calculate the number of hotel days.

  1. First, determine the check-in date (Cin).
  2. Next, determine the check-out date (Cout).
  3. Next, compare the two calendar dates at the same UTC reference time so daylight-saving changes do not affect the count.
  4. Finally, divide the difference by 86,400,000 milliseconds per day to get the number of nights. The example below is 4 nights.
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Check-In Date (Cin) = 2023-10-01

Check-Out Date (Cout) = 2023-10-05; length of stay = 4 nights.