What are BTUs?

What are BTUs?

When shopping for a new gas grill, you want the most bang for your buck, right? More often than not, BTU is one of the first factors you’ll consider. However, higher BTUs don’t necessarily mean a hotter grill. In fact, higher BTUs may mean that energy is being wasted to achieve and maintain temperatures. Today's grills are more efficient and don't need as much BTU output as they once did. In this article, we'll tell you what BTUs are, why they're important and how many you need.

what is btu?

BTU [British Thermal Unit] is a measurement of the total heat output and fuel consumption per hour. On the most basic level, it’s the amount of thermal energy needed to raise the temperature of one pound of water by one degree, specifically from 39°F to 40°F.

What does BTU mean for a gas grill?

In the grilling industry, BTUs are a measurement of how much heat a gas grill generates at its maximum output. Think of BTU as a fuel efficiency rating not how hot your grill will get. Like your car’s fuel efficiency or MPG (miles per gallon), BTUs measure your grill’s fuel efficiency or OPB (output per burner). It can be listed on a per burner basis or as the total number of BTUs for all burners combined. Since the number of BTUs for all burners combined is a bigger, more impressive number, this number is often used to sell grills. Sometimes, the BTU of the side burners may be included for an even bigger number. Look closely at the numbers to be sure you know exactly what the BTU rating represents.

How do you get more heat out of your grill?

Airflow is a critical factor in reaching and maintaining cooking temps. Even if a grill has the highest BTU rating, if it doesn’t have good airflow, it won’t necessarily be hotter. It will also very likely have hot and cold spots.

When you’re in the market for a new grill, look for solid construction. Check how well the lid fits the body. If it fits snugly and the grill's components are well made, it will likely heat up quickly and maintain cooking temps. The most important features to look for are even heat and the ability to sear. So, again higher BTU doesn't mean a hotter grill. And when you really think about it, most grilling isn’t done at the highest temperature setting.

What is the BTU rating of an Amplifire gas grill?

Amplifire™ gas grills have BTU ratings that are 7,000 to 10,000 lower than most open flame grills, making this type of grill one of the most efficient on the market. Since emitter plates efficiently manage and distribute heat across the cooking surface, heat is quickly and efficiently transferred directly to your food rather than the air surrounding your food, using less fuel.

What is heat flux?

Heat output of a grill is better gauged by heat flux, the amount of heat per square inch. To calculate your grill’s heat flux, divide the total BTU rating by the primary cooking area. The number you want is for the main burners combined, not including warming racks or side burners. Many times, a grill with a higher BTU rating provides less heat overall due to a large grilling area.

 For example:

  •       A 4-burner grill with 48,000 BTUs and a 500-square-inch cooking area will have a heat flux of 96.
  •       A 5-burner grill with 60,000 BTUs and a 700-square-inch cooking area will have a heat flux of 85.
  •       A 6-burner grill with 72,000 BTUs and a 900-square-inch cooking area will have a heat flux of 80.


When purchasing a standard open flame grill, we recommend 80 to 100 BTUs-per-square-inch. For an Amplifire™ grill, 50 to 80 BTUs will be all you need. 

Is higher BTU better for grilling?

Higher BTUs are often associated with better performance. However, much of the information you’ll find can be misleading, giving the impression that grills with higher BTU ratings will be hotter. How well the grill disperses heat for even cooking is not a factor of BTUs. Although BTU rating influences temperature, it’s far from the only factor that determines how hot your grill will get.

Beware of BTU ratings that are either extremely high or low. Grills with extremely high BTU ratings may be calculated in a deceptive manner or have inferior design and construction. Remember, BTU rating indicates the amount of fuel used per hour. A grill with a high BTU rating will require more fuel than a grill with a lower rating. Grills with BTU ranges that are lower than standard recommendations will likely be slow to preheat and slow to get back up to cooking temperatures after opening the lid to check on your food.

How many BTUs should a side burner have?

A side burner usually has between 10,000 and 13,000 BTUs. The side burner uses less fuel per hour in comparison to the main or primary burners because it heats a smaller cooking area.

What is a good BTU for gas grills?

BTU ratings give you an idea of how much fuel a grill will burn per hour. The bigger the cooking area is, the higher the number of BTUs and the more fuel you will go through. Large grills with large cooking areas require more fuel and have higher BTU ratings. Small grills with smaller cooking areas require less fuel to achieve the same results and have lower BTU ratings. Evaluate based on heat flux, the amount of heat per square inch, to know the true efficiency and power of your grill.

Bottom line, when looking for a new gas grill, don’t let the BTU rating be the most important factor. Think of the BTU number as a fuel efficiency rating not how much heat the grill produces. Should you consider BTUs as one of the factors? Absolutely. Consider the total BTUs, the primary cooking area and the number of BTUs-per-square-inch. But don’t let that be the deciding factor in your purchase. Keep in mind that other factors like construction, heat retention and burner placement can all affect a grill’s performance. Look at all of the grill’s features, including the warranty, before making your decision.

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