Enter the maximum temperature, minimum temperature, and base temperature into the calculator to determine the degree days. This calculator can also evaluate any of the variables given the others are known.

## Degree Day Formula

The following formula is used to calculate the degree days.

DD = (Tmax + Tmin) / 2 - Tbase

Variables:

- DD is the degree days Tmax is the maximum temperature for the day (°C or °F) Tmin is the minimum temperature for the day (°C or °F) Tbase is the base temperature (°C or °F)

To calculate the degree days, add the maximum temperature for the day to the minimum temperature for the day. Divide the result by 2 to get the average temperature for the day. Subtract the base temperature from the average temperature to get the degree days.

## What is a Degree Day?

A Degree Day is a measurement used in weather forecasting and energy management to quantify the demand for heating or cooling in buildings. It represents the difference between the average outdoor temperature in a 24-hour period and a standard base temperature (usually 65 degrees Fahrenheit or 18 degrees Celsius). If the average temperature is above the base, it’s a Cooling Degree Day, indicating a need for air conditioning. If it’s below the base, it’s a Heating Degree Day, indicating a need for heating. This helps in estimating energy consumption and costs.

## How to Calculate Degree Day?

The following steps outline how to calculate the Degree Day using the formula: DD = (Tmax + Tmin) / 2 – Tbase

- First, determine the maximum temperature for the day (Tmax) in °C or °F.
- Next, determine the minimum temperature for the day (Tmin) in °C or °F.
- Next, determine the base temperature (Tbase) in °C or °F.
- Use the formula DD = (Tmax + Tmin) / 2 – Tbase to calculate the Degree Day.
- Finally, calculate the Degree Day using the obtained values.

**Example Problem:**

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

Tmax = 25°C

Tmin = 15°C

Tbase = 10°C