How Much Propane Do Heaters Use? (Propane BTU Calculator)

Propane heaters use propane. How much propane exactly? It is a good idea to understand how much propane do heaters use in order to plan your propane usage. Obviously, the size of the propane heater (measured in BTU/h) is the primary factor that determines the heater’s propane usage.

To help you out, we have created a Propane BTU Calculator, along with the propane heater usage per hour, day, and month chart for 5,000 BTU to 200,000 BTU propane heaters.

Example: How much propane does a 30,000 BTU patio heater use? Using the propane BTU calculator below (and presume 90% efficiency), we see that a 30,000 BTU heater will use 0.36 gallons of propane per hour. That’s about 1.48 lb of propane (we presume 4.11 lb/gallon propane density at 77°F).

how much propane do propane heater use per hour
How long will a propane tank last (powering a propane heater)  depends on how much propane will a heater use. 30,000 BTU heater, for example, uses about 1/3 gallon per hour (about 1.5 lb).

As you can see, there are only 2 factors that determine how much propane will a heater use, namely:

  1. Propane Heater Size (In BTU/h or British Thermal Units). We have 10,000 BTU, 20,000 BTU, and 30,000 BTU propane heaters, and so on. This can be a garage propane heater, patio propane heater, etc. The size – of propane heater heating capacity – is the heating output a unit will give off. The bigger the propane heater, the more propane it will burn.
  2. Propane Heater Efficiency (In %). This is the amount of heat the propane heater can extract from 1 lb or 1 gallon of propane. Most propane heaters will have a 90% efficiency or higher. Example: 1 gallon of propane contains 91,452 BTU of energy. A 90% efficient propane heater will be able to convert that gallon of propane into 82,307 BTU of heating output. The rest – 10% of the total or 9,152 BTU – are the propane burning losses.

Now, to calculate the propane heater usage, we will need this 1 key data point:

1 gallon of propane contains 91,452 BTU. (Provided by the US Energy Information Administration)

If we know what size propane heater we have and how efficient it is (we usually presume 90% efficiency), we can easily calculate how much propane will any propane heater use with this formula:

Propane Usage = Propane Heater Capacity (In BTU) / (91,452 BTU Per Gallon × Efficiency (%) / 100)

Example of how to use this formula: How much propane does a 50,000 BTU heater use? We presume 90% efficiency and insert everything in the equation:

50,000 BTU Propane Usage = 50,000 BTU / (91,453 BTU/gallon × 90%/100) = 0.61 Gallons Of Propane Per Hour

A 50,000 BTU propane heater will consume 0.61 gallons of propane per hour. If you want to know how many lb of propane is that, you can multiply the number of gallons by 4.11 lb/gallon. In the case of a 50,000 BTU heater, we get 2.51 lb propane usage per hour.

All these calculations can be a bit complex and take some time to figure out. To help you out, we have prepared a simple propane BTU calculator you can freely use. Below the calculator, you will also find the calculated propane usage for 5,000 BTU – 200,000 BTU propane heaters per hour, per day, and per month:

Propane BTU Calculator Per Hour

In this calculator, you just input the capacity of your propane heater (BTUs) and its efficiency. If you don’t know the efficiency specs, you can just input the 90% efficiency. The calculator will automatically calculate how much propane will your heater use per hour:


Here is an example of how to use this calculator:

Let’s say you have a 48,000 BTU propane heater. How much propane will it use? Just slide the 1st slider to ‘48,000’ and the second slider to ’90’. You get the result: This 48,000 BTU propane heater will use 0.58 gallons of propane per hour.

This is just one example. We have used this calculator to calculate the amount of propane do 5,000 BTU to 200,000 BTU heaters use, and summarized the result in this chart:

Propane Heater Usage Per Hour, Day, Month

Propane Heater BTU Rating: Propane Usage Per Hour: Propane Usage Per Day (8 Hours): Propane Usage Per Month (8h/day):
5,000 BTU 0.06 Gallons Per Hour 0.48 Gallons Per Day 14.4 Gallons Per Month
10,000 BTU 0.12 Gallons Per Hour 0.96 Gallons Per Day 28.8 Gallons Per Month
15,000 BTU 0.18 Gallons Per Hour 1.44 Gallons Per Day 43.2 Gallons Per Month
20,000 BTU 0.24 Gallons Per Hour 1.92 Gallons Per Day 57.6 Gallons Per Month
25,000 BTU 0.30 Gallons Per Hour 2.40 Gallons Per Day 72.0 Gallons Per Month
30,000 BTU 0.36 Gallons Per Hour 2.88 Gallons Per Day 86.4 Gallons Per Month
40,000 BTU 0.49 Gallons Per Hour 3.92 Gallons Per Day 117.6 Gallons Per Month
50,000 BTU 0.61 Gallons Per Hour 4.88 Gallons Per Day 146.4 Gallons Per Month
60,000 BTU 0.73 Gallons Per Hour 5.84 Gallons Per Day 175.2 Gallons Per Month
70,000 BTU 0.85 Gallons Per Hour 6.80 Gallons Per Day 204.0 Gallons Per Month
80,000 BTU 0.97 Gallons Per Hour 7.76 Gallons Per Day 232.8 Gallons Per Month
90,000 BTU 1.09 Gallons Per Hour 8.72 Gallons Per Day 261.6 Gallons Per Month
100,000 BTU 1.21 Gallons Per Hour 9.68 Gallons Per Day 290.4 Gallons Per Month
150,000 BTU 1.82 Gallons Per Hour 14.56 Gallons Per Day 436.8 Gallons Per Month
200,000 BTU 2.42 Gallons Per Hour 19.36 Gallons Per Day 580.8 Gallons Per Month

As you can see, you have quite a lot of propane usage results here.

Example: How much propane will an 80,000 BTU heater use?

If we presume 90% efficiency, an 80,000 BTU propane heater will use:

  • 0.73 gallons of propane per hour.
  • 5.84 gallons of propane per day (if we run the heater for 8 hours per day).
  • 175.2 gallons of propane per month (8 hour/day usage).

With the calculator and this chart, you can adequately estimate how many gallon of propane will different propane heaters use. If you need any assistance, you can give us some relevant numbers (BTUs, for example) in the comment section below, and we will try to help you out as best we can.

8 thoughts on “How Much Propane Do Heaters Use? (Propane BTU Calculator)”

  1. I did not know that my rental was heated with propane. I found out the hard way and have been sitting in the cold for 3 days and counting. I plan to buy a couple of extra tanks so switching them will be easier. Temps in the 20s here. No response from landlord and I’ve been told that I need my own account number. Does this make sense?

    • Hi Suzanne, well, that’s not a good situation to find yourself in. The best thing really would be to get in contact with the landlord; he or she will have information about what to do with the propane heating. Hope you can get in touch with him or her soon, 20-degree temperatures are cold.

  2. It’s currently 22 degrees outside and very windy. I am using thirty gallons of propane a day. There has to be a leak somewhere but we can’t smell gas anywhere.

    • Hi Jim, 30 gallons of propane per day is quite a lot. You basically empty a 500-gallon propane tank (holds 400 gallons, 80% rule) in 13-14 days. In terms of BTUs, that’s 2,743,560 BTU per day. That means you are burning more than 100,000 BTU per hour, or that something is leaking somewhere.

      The leak might be in the outdoor residential propane tank. You have probably tried to smell gas there, right? Well, the low temperature (22 degrees) means that the propane is not all that volatile and doesn’t smell as much. Add wind to that – wind is blowing the propane vapor away, dispersing it – and you will hardly be able to smell gas if there is a leak.

      If you are not using a bunch of that propane for heating (over 100,000 BTU per hour), it might be good to call somebody to professionally check the propane tank for leaks. Hope this makes sense.

  3. We have propane to heat our house we converted our garage into a craft room. It is well insulated but we have been heating it with an electric floor heated .(very expensive to run) could you please give us some advice. The room is approx. 350sq ft.

    • Hi Marcia, you could use the propane heating for your new craft room as well. Electric floor heating can be a bit expensive, that’s true. For a 350 sq ft well-insulated room, you would need about 7000 BTU (20 BTU per sq ft) of heating output. That is equal to 2.05 kW electric heating.

      Basically, your electric floor heating will use 2.05 kWh per hour. If your electricity price is $0.15/kWh, that’s about $0.31 per hour. If you run it 24/7 at 100% output, that comes to $7.38 per day and $221.40 per month. Yeah, that’s quite a lot.

  4. Ok…Mt propane heater shuts itself on and off. I have been reading so I can learn about propane usage and budget accordingly. (I am retired). My heater said it was a 30k BTU unit. However, the thermostat is from 1 to 5, and I generally keep it at a 2. Now, I have 2 questions…

    1) is my heater actually burning 30k btu’s if my thermostat is at 2?

    2) if it is not running, how many btu’s does the pilot light use, and should the 30,000 btu’s be used to calculate usage?

    • Hi Deb, that 1 to 5 is usually not a thermostat but BTU output setter. If you have a 30k BTU unit, 5 usually means you have 100% output; so 30k BTU. That 2 setting will not have a 30k BTU output. You will likely have a 10k to 20k BTU at that level (the manual may indicate how much exactly). Pilot light does burn a noticable amount of propane, we delved into this in our article about how much gas does a pilot light use here.


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