How to Calculate per Diem Rate

by

Per Diem Rate Calculator

This calculator helps you determine the average daily per diem rate based on your total lodging and M&IE (Meals & Incidentals) costs over a specific period.

function calculatePerDiem() { var totalLodging = parseFloat(document.getElementById("totalLodging").value); var totalMIE = parseFloat(document.getElementById("totalMIE").value); var numberOfDays = parseFloat(document.getElementById("numberOfDays").value); var resultDiv = document.getElementById("result"); if (isNaN(totalLodging) || isNaN(totalMIE) || isNaN(numberOfDays)) { resultDiv.innerHTML = "Please enter valid numbers in all fields."; return; } if (numberOfDays <= 0) { resultDiv.innerHTML = "Number of days must be greater than zero."; return; } if (totalLodging < 0 || totalMIE < 0) { resultDiv.innerHTML = "Costs cannot be negative."; return; } var perDiemRate = (totalLodging + totalMIE) / numberOfDays; resultDiv.innerHTML = "Average Per Diem Rate: $" + perDiemRate.toFixed(2) + " per day."; }

Understanding Per Diem

Per diem, Latin for "per day" or "for each day," is a daily allowance an organization provides to individuals, typically employees, to cover living expenses when traveling for work or on temporary assignment away from home.

What Does Per Diem Typically Cover?

Per diem allowances are generally intended to cover:

  • Lodging: Costs for hotel rooms or other accommodation.
  • Meals: Breakfast, lunch, and dinner expenses.
  • Incidentals (M&IE): This combined category often includes meals and incidental expenses like tips for services, laundry, and other small, necessary costs incurred while traveling.

The specific amounts and what's covered can vary significantly based on the organization (government, private company), the travel location (costs vary by city and country), and the time of year.

How are Per Diem Rates Determined?

Many organizations, especially government agencies like the U.S. General Services Administration (GSA), establish fixed per diem rates for various locations. These rates are based on the average cost of lodging and M&IE in those areas. Companies may adopt these government rates or set their own based on their policies and travel needs.

The calculator above helps you find an average daily rate if you know your total costs for lodging and M&IE over a period, rather than using a pre-set rate.

Calculating Average Per Diem Rate

If you have the total costs and the number of days, you can calculate the average daily per diem rate as follows:

Average Per Diem Rate = (Total Lodging Cost + Total M&IE Cost) / Number of Days

Example:

Suppose you went on a 5-day business trip:

  • Total Lodging Cost: $750
  • Total M&IE Cost: $350
  • Number of Days: 5

Average Per Diem Rate = ($750 + $350) / 5 = $1100 / 5 = $220 per day.

This means your average daily expense for lodging and M&IE was $220.

When using pre-set rates for a location, the calculation for the total allowance would be:

Total Allowance = (Daily Lodging Rate x Number of Nights) + (Daily M&IE Rate x Number of Days)

Note: Sometimes the M&IE rate is reduced for the first and last day of travel.

Leave a Comment