How Many Patio Heaters Do I Actually Need?

I was having a discussion with an old boss of mine a few months ago about the upcoming winter season. For a bit of back story, he has a gorgeous stamped concrete patio surrounding his in-ground pool.

He and his wife built it a couple of years ago and immediately fell in love with it. During of conversation, he was lamenting the fact that he was going to have to winterize the patio in a few short weeks.

Last winter, he and his family spent far too much time indoors and far too little time enjoying the great patio that he just had built. So I did what any good friend would do — I recommended he pick up a much-needed patio heater!

The drinks kept flowing and we started talking about how many patio heaters he would actually need. He knows about my undying love for all things outdoor, so I assured him I’d research the question.

As of this morning, the research is complete and I’m ready to share my findings. So buckle up, I’m about to tell you how many patio heaters you need based on the size of your patio.

I’m happy to report that the answer is usually 1 or 2 patio heaters. However, if you think your outdoor space needs more than that, read on to find out if you’re right.

Considerations

First, let’s go through all of the factors that will ultimately effect how many patio heaters you need to purchase. Each one alters your needs slightly and you shouldn’t ignore any of them.

Size of Space

This should come as no surprise, but the size of your space is the #1 consideration for choosing how many heaters to buy for your patio. Generally, you’ll need 1 patio heater for every 1500-2000 square feet of covered space.

I should note that you shouldn’t expect 1 patio heater to actually heat this amount of space. However, it’s unlikely that you’ll want to heat the entire patio anyway (more on this later).

You may have noticed that the above numbers are for covered patios only. But what about uncovered patios? For that situation, you should only expect a freestanding patio heater to cover a 20-foot diameter (or roughly 314 square feet total).

You’ll recall from science class that heat tends to rise and without a ceiling, the sky is literally the limit. This was the situation my old boss was in and we had to adjust his number of patio heaters accordingly.

BTU Output

Naturally, if the heat output of your patio heater is on the lower side, you’re going to need more of them to cover an area.

You can expect good free-standing patio heaters to have between 30,000 and 50,000 BTUs, although you may not need to utilize the full amount. Here’s a handy table to see roughly how much BTU output you’ll need for a given area.

Area	BTU Estimate
100-450 sq. ft. (~9-42 sq. meter)	5,000 – 10,000
450-1,000 sq. ft. (~42-93 sq. meter)	10,000 – 20,000
1,000-1,500 sq. ft. (~93-139 sq. meter)	20,000 – 24,000
1,500-2,000 sq. ft (~139-186 sq. meter)	24,000 – 30,000
2,000-2,500 sq. ft (~186-232 sq. meter)	30,000 – 34,000

If you’re concerned, more is usually better. Most high-quality patio heaters (like this one) allow you to reduce the heat as necessary.

Positioning

As I alluded to above, it’s unlikely that you’re going to need to heat your entire patio area.

In fact, it’s often better to have a small number of targeted patio heaters rather than a large number of general-purpose ones. For a concrete example, you might put one close to your patio dining set and another underneath your pergola.

In this example, those are the two places folks are most likely to congregate. We don’t have a reason to heat the space where no one is!

For my old boss, he decided to buy three and put them in these targeted locations:

1. Right outside his patio door (his wife is a smoker).
2. Next to his pool furniture.
3. Close to his grill / outdoor kitchen.

If you’re not sure about positioning, consider getting a patio heater on wheels so that it’ll be much easier to move (find my reviews for them here).

Safety

Last but not least, you want to make sure that you’re not putting your property or your life in danger with your heater placement. It’s not worth risking life and limb just to be more comfortable during the wintertime. Follow the rules and make sure you’re not doing anything dangerous. What are the rules, you ask?

So, How Many?

To sum up everything I’ve covered so far, here’s how many patio heaters you’ll need for your outdoor space.

If you have a covered patio, you should only need a single free-standing, high BTU output patio heater per 1500 square feet. However, take care to make sure the heater is nowhere near combustible items (rugs, patio furniture cushions, wooden structures).

If you have an uncovered patio, you’ll need as many free-standing patio heaters as you have locations where people congregate. Be sure to target the most heavily trafficked locations and follow all safety advice above.