How Much Does It Cost to Run a Patio Heater? Electric vs Propane

Patio Heater Running Cost at a Glance

This table shows the patio heater running cost at full power, using the EIA average prices above for electricity and bulk propane, and an example price of $25 per cylinder for refills and exchanges.

Your own patio heater running cost will be different if your electricity rate or cylinder price is higher or lower. The next sections show how to calculate it in a minute.

Electric Patio Heater Cost per Hour

An electric patio heater uses its rated wattage every hour it runs at that setting. To find the cost to run a patio heater on electricity, convert watts to kilowatts and multiply by your electricity price.

Cost per hour = (watts ÷ 1,000) × price per kWh
Example: 1,500 W ÷ 1,000 × $0.1831 = about $0.27 per hour.

Electricity prices vary a lot between states, so look for the price per kWh on your own bill: it has the biggest effect on your electric patio heater running cost. Use the energy charge plus any delivery charge per kWh; the fixed monthly fee does not change when you switch on a heater.

Does an infrared heater use less electricity?

No. A 1,500 W infrared heater uses exactly as much electricity per hour as any other 1,500 W heater. The difference is how it feels: infrared warms the people and objects it points at, not the air, so you may be comfortable on a lower setting. That lower setting is where you save on the cost to run a patio heater. Our patio heater BTU and sizing guide shows how many watts a seating area needs.

Propane Patio Heater Cost per Hour

A propane heater is rated in BTU per hour at its highest setting. The EIA puts the energy in one gallon of propane at about 91,452 BTU, so you can work out how much propane a heater burns per hour and what the cost to run a patio heater on propane will be.

Gallons per hour = BTU rating ÷ 91,452
Cost per hour = gallons per hour × price per gallon
Example: 46,000 ÷ 91,452 = 0.503 gallons per hour; × $2.598 = about $1.31 per hour.

These figures are for the highest setting. On a lower setting the heater burns less, but not necessarily in proportion to the knob, so use the full-power numbers to budget safely. The bulk price is what households with a large delivered tank pay; most patio heaters run on cylinders, which usually cost more per gallon, as the next section shows.

Refill vs Exchange: What a Propane Tank Really Costs

For a cylinder, the easiest way to find your patio heater running cost per hour is to divide what you paid by how many hours the tank lasts. Two details make a big difference:

• Refills fill a standard 20 lb cylinder with about 4.7 gallons of propane, and you usually pay per gallon.
• Exchange tanks are often not full: Blue Rhino states that its exchange cylinders contain 15 lb of propane, so you get about a quarter less fuel for a similar price.

The tank prices are examples, not quotes; check your own receipt. What the table shows holds everywhere: at the same price, an exchange tank with 15 lb costs about a third more per hour than a full 20 lb refill. Over a season, that choice affects your patio heater running cost more than the brand of heater does.

How Long Does a Propane Tank Last on a Patio Heater?

A full 20 lb cylinder holds about 430,000 BTU of energy, a 15 lb fill about 322,500 BTU and a 1 lb cylinder about 21,500 BTU, by our calculation from the EIA figure. Divide that by the heater rating to estimate the runtime at full power:

Cold weather lowers the pressure in a cylinder, so a tank can run out a little sooner on a very cold night. If you entertain often, keep a spare cylinder, stored upright outdoors and away from the heater.

Patio Heater Running Cost Calculator

Enter your own heater rating, energy price and hours of use to see the cost to run a patio heater in your situation. Prefilled values use the EIA averages. For a cylinder, enter your tank price divided by the gallons in it: a full 20 lb tank holds about 4.7 gallons, a 15 lb exchange about 3.5.

What Will a Patio Heater Add to Your Monthly Budget?

Suppose you use one heater for three hours on two evenings a week. Over four weeks, that is 24 hours of use. With the prices in this guide, the monthly patio heater running cost looks like this:

• 1,500 W electric heater: 24 × $0.27 = about $6.59 a month.
• 46,000 BTU propane, bulk price: about $31.36 a month.
• 46,000 BTU propane, $25 per 20 lb refill: about $64.19 a month, or roughly 2.6 tanks.
• 46,000 BTU propane, $25 per 15 lb exchange: about $85.58 a month, or roughly 3.4 tanks.

We calculated with unrounded hourly costs, so multiplying the rounded figures may differ by a few cents. Two heaters double your patio heater running cost. Remember to set aside money for the purchase itself, a first cylinder or the electrical work for a hardwired heater; none of that is in the fuel costs.

Cost per Hour vs Warmth: Comparing Fairly

A lower patio heater running cost per hour does not automatically mean the cheaper choice. A 46,000 BTU propane tower releases about nine times more heat than a 1,500 W electric heater, which puts out about 5,100 BTU per hour. They are made for different jobs: the tower warms a circle around a group on an open patio, the electric heater a small zone for one or two people.

Per unit of heat, propane is actually the cheaper fuel. At the EIA averages, bulk propane costs about $28 per million BTU and electricity about $54 per million BTU, by our calculation. Cylinder refills and exchanges narrow or erase that gap. So the fair question is not “which fuel is cheaper?” but “what is the cost to run a patio heater that keeps my seating area comfortable?” Our propane vs electric patio heater guide compares the two types on heat, installation and safety, and our patio heater BTU guide helps you size the heater to your patio.

How to Lower the Cost to Run a Patio Heater

1. Heat the seats, not the yard. Aim the heater at the seating area and place it close to where people sit, within the clearances in the manual.
2. Use the lowest comfortable setting. On an electric heater, the 900 W setting costs about 40 percent less than 1,500 W.
3. Block the wind. A hedge, screen or wall on the windward side keeps the warmth where you sit. Never enclose a propane heater.
4. Refill instead of exchange. A full 20 lb refill gives you about a third more propane than a 15 lb exchange tank.
5. Turn it off when you go inside. A heater warming an empty patio still uses fuel.
6. Dress for the evening. Blankets and a warm rug let you run the heater on a lower setting. Our winter patio ideas have more tips.

Safety comes before savings. Do not run an electric heater on an extension cord, timer or smart plug unless the manufacturer allows it, and never use a propane heater in an enclosed space. Read our guide to using a patio heater under a covered patio before you place one under a roof.

Common Patio Heater Running Cost Mistakes

• Comparing a 1,500 W heater with a 46,000 BTU tower on hourly cost alone, while they heat very different areas.
• Assuming an exchange tank holds 20 lb of propane.
• Dividing the whole electricity bill, including fixed fees, by the hours of heater use.
• Expecting an infrared heater to use less electricity than another heater with the same wattage.
• Budgeting with the low setting, then running the heater on full all evening.
• Forgetting that two heaters on a large patio double the patio heater running cost.

Patio Heaters to Consider

These two heaters match the electric and propane examples in this guide, so you can see the cost to run a patio heater of each type. They are part of our best patio heaters comparison, where you will find six more models and their trade-offs.

Prices and availability on Amazon change often. Check the listing and the manual for the current output, clearances and certifications before you buy.

Related Guides

• Best patio heaters: 8 models compared
• Propane vs electric patio heater: which is better?
• How many BTUs do you need for a patio heater?
• Can you use a patio heater under a covered patio?
• How to enjoy your patio during winter

Frequently Asked Questions