What are Degree Days for Heating Oil?

A degree day is a unit of measurement for how cold (or hot) the temperature has been over a 24-hour period. Whenever that average temperature is below 65 degrees Fahrenheit, that counts as a degree day. 

Heating oil suppliers like us use degree days along with a few other factors to estimate when to schedule a customer’s next automatic oil delivery. 

Here’s everything you need to know:

How to Calculate Degree Days

To calculate daily degree days, we add the day’s high and low temperatures together, divide by 2, and then subtract the answer from 65.

Here’s an example:

High Temperature: 50
Low Temperature: 34

50 + 34 = 84 

84 ÷ 2 = 42 (This is the average temperature for that day)

65 – 42 = 23 Degree Days

What's K-Factor, and how is it used?

The K-Factor shows how fast a customer uses fuel:

  • The higher the K-Factor number, the more fuel burned
  • The lower the K-Factor number, the less fuel burned

Each home has a unique K-Factor depending on things like the size of your home, how well it’s insulated, thermostat settings, equipment efficiency, and more.

The formula to calculate the K-Factor is pretty simple — you just divide the elapsed degree days by the number of gallons of oil needed to fill your tank. For example: 

2,000 Degree Days ÷ 400 Gallons = a K-Factor of 5

We use K-Factor (the rate at which you burn heating oil) in combination with Degree Days (the average temperature trends) to estimate both when you’ll need a fill-up and how many gallons to bring.

The Bottom Line

Degree Days and K-Factor are the calculations that let us offer automatic heating oil delivery by allowing us to estimate when you’ll need it next.

Instead of having to constantly monitor their tank levels or even risk the danger of completely running out of heating oil, our customers can safely rely on us to arrive on time, every time, for their next fill-up. They also get to enjoy the financial benefits of this cost-effective system.

Interested in setting up automatic heating oil delivery for your home? Give us a call.