How Long Does A 250-Gallon Propane Tank Last For A House?

250-gallon propane tanks are primarily used for winter heating. With a 250-gallon residential tank, you can heat up your entire house. The key question here is this:

How long does a 250-gallon propane tank last for a house?

250 Gallon Propane Tank Size And Dimensions
Example of an above-ground 250-gallon propane tank. You can check out 250-gallon propane tank dimensions here.

Here’s the short answer:

A 250-gallon propane tank lasts for anywhere between 26 days to 7 months and 2 days. That’s quite a wide range. The longevity of a 250-gallon propane tank depends on use (how much propane per day you burn). This is indirectly connected with how big a house you want to heat with a 250-gallon propane tank.

If you want to use a residential propane tank for heating, you have to calculate how long will it last. There are two ways how to calculate that (we use both of them further on), namely:

  1. By heating demand. This is the harder way; you have to estimate your average heating demand in the 6 winter months. Example: A house with 20,000 BTU heating demand will burn throughout a 250-gallon propane tank in 37-38 days.
  2. By house size. This is the easier way. Obviously, the 250-gallon propane tank will last much longer heating a small 500 sq ft house than heating a big 4,000 sq ft house. If you check the analysis of how long do propane tanks last here, you can see that an average US household (2,200 sq ft house) uses about 750 gallons of propane for heating in 6 winter months (October through March). We can use these average propane heating consumption to calculate how long will a 250-gallon propane tank last for any house size.
    how much propane we need for heating in the winter
    On average, a US household will burn through 750 gallons of propane every winter. Data Source: US Energy Information Administration

We also need to take into account that a full 250-gallon tank holds 200 gallons of propane. This is the 80% rule for all residential tank sizes; it is a safety measure.

Let’s first look at how you can calculate how long will a 250-gallon propane tank last for heating via heating demand. After that, we will also look at how long will this tank last for 500, 1000, 1500, 2000, 2500, 3000, 3500, and 4000 sq ft houses:

Method 1: How Long Will A 250-Gallon Propane Tank Last (By Heating Demand)

Here we will determine how much energy does a 250-gallon propane tank hold. Then comes the tricky part – evaluating how much energy you need for heating. Based on this, we can calculate how long should a 250-gallon propane tank last.

1 gallon of propane contains 91,500 BTU of heating energy. In a full 250-gallon propane tank, we have 200 gallons of propane. Here is how much energy such a 250-gallon propane tank hold:

Energy Content (250-Gallon Tank) = 200 Gallons × 91,500 BTU/Gallon = 18,300,000 BTU

That means that a 100% full 250-gallon propane tank holds almost 20 million BTU of heating energy.

Now we need to determine how many BTUs we use to heat our home. Small homes require as little as 5,000 BTU/h and the biggest homes require more than 50,000 BTU/h. This is the average hourly heating output in the 6 winter months (it’s notoriously difficult to evaluate; that’s the primary reason why we use the following easier Method 2 for this calculation).

Example: Let’s say we have a house that requires 15,000 BTU of heat every hour. We know that the 250-gallon propane tank holds 18,300,000 BTU of energy. How long will this energy from the 250-gallon propane tank last? Here’s how we can calculate that:

How Long Will 250-Gallon Tank Last = 18,300,000 BTU / 15,000 BTU/h = 1,220 h =

50 Days And 20 Hours

As you can see, for such heating demand, a 250-gallon propane tank will last 10 days shy of 2 months.

We have calculated how long will a 250-gallon propane tank based on different heating needs. Here is the full calculated table:

Heating Need (BTU/h): 250-Gallon Tank Lasts For:
5,000 BTU/h 153 days
10,000 BTU/h 76 days
20,000 BTU/h 38 days
30,000 BTU/h 25 days
40,000 BTU/h 19 days
50,000 BTU/h 15 days

Admittedly, it’s very hard to evaluate the heating need precisely enough. That’s why we use an easier method to determine how long will a 250-gallon propane tank last (based on house size):

Method 2: How Long Will A 250-Gallon Propane Tank Last For 500-4,000 Sq Ft Houses

Here we use average US propane consumption for heating per household data from Statista. In short, on average, a US household (2,200 sq ft) uses about 750 gallons of propane for heating during the 6 colder months (October through March).

That means that we, on average, need about 0.341 gallons of propane for heating 1 sq ft of our house. To illustrate, 1 gallon of propane is equal to 4.25 lbs; we need about 1.45 lbs of propane per square foot for heating.

With this, we can get a good estimate of how long will a 250-gallon propane tank last for any house size.

Example: Let’s say we have a 1,500 sq ft house and use a 250-gallon propane tank for heating. We know that it holds 200 gallons of propane, when full, and that we require about 0.341 gallons of propane per square foot to keep our house warm. Let’s first calculate how much propane we need for heating in 6 colder months;

How Much Propane (6 Months) = 1,500 sq ft × 0.341 gallons / sq ft  = 511.5 Gallons

That means we will need 511.5 gallons in total for heating an average 1,500 sq ft house. This is a 6-month worth of propane.

Now, a 250-gallon propane tank holds 200 gallons. If we need 511.5 gallons for heating, we will need to refuel the propane tank twice per season. What is more, we can now calculate how many months/days the 250-gallon propane tank is good for like this:

How Long Will 250-Gallon Tank Last = (200 gallons / 511.5 gallons) × 180 Days = 70.4 Days = 2 Months, 10 Days, 10 Hours

Here you have it; a 250-gallon propane tank will be able to heat an average 1,500 sq ft house for more than 2 months.

We have calculated how long will this size of propane tank last for different house sizes. Here is the full calculated table:

House Size (Square Footage): How Long Will A 250-Gallon Propane Tank Last?
500 sq ft 7 Months and 2 Days
1,000 sq ft 3 Months and 16 Days
1,500 sq ft 2 Months and 11 Days
2,000 sq ft 1 Month and 23 Days
2,500 sq ft 1 Month and 12 Days
3,000 sq ft 1 Month and 5 Days
3,500 sq ft 1 Month
4,000 sq ft 26 Days

You can use this table as a good estimate of how long will a 250-gallon propane tank.

For other residential tank sizes, you can check the following articles:

If you have any questions, or have difficulties calculating all of this yourself, you can send us a comment below and we’ll try to help you out as best we can.

4 thoughts on “How Long Does A 250-Gallon Propane Tank Last For A House?”

  1. I have to run a 12000 watt generator about 4-5 hours every 5 days to charge my solar batteries. I use the 220 amp plug for the power production. Approximately how much propane would I need to last from November to March?

    Reply
    • Hi Jim, alright, here is how we can tackle this one: From November to March, we have 5 months (150 days). Running the generator every 5 days means you will be running it 30-times per winter. Each time you run it, you are producing 12,000 watts for 4-5 hours, resulting in 48 kWh to 60 kWh output. 30-times that is 1440 kWh to 1800 kWh.
      Now, we know that a gallon of propane contains about 91,500 BTU per gallon of heat content. A good propane generator will have a 20% efficiency. That means it will be able to turn 18,300 BTU of heat content per gallon into usable electricity.

      Now we have to convert these BTU to kWh (you can use this calculator). 1 BTU is equal to 0.00029308323 kWh. That means each gallon of propane will produce about 5.36 kWh of electricity.

      You need anywhere from 1440 kWh to 1800 kWh of electricity. If you divide these numbers by 5.36 kWh per gallon, you get the result: You would need anywhere between 269 and 336 gallons of propane.

      Now, a 250 gallon propane, when full, holds 200 gallons of propane. This will be sufficient to fill your solar batteries from November to about February.
      Hope this calculation helps.

      Reply
  2. What size propane tank would I need for a tankless water heater for 3 full-size bathrooms, stove and a gas fireplace. The furnace is electric.

    This is a vacation home that we are at about 1-1/2 weeks a month.

    Reply
    • Hi Mark, for vacation homes, most people usually go with smaller 100-gallon or 250-gallon propane tanks. With a 100-gallon tank, you will have to refuel it more frequently but it’s cheaper and smaller than a 250-gallon tank. Just avoid bigger 500-gallon or 750-gallon tanks, that would be overkill.

      Reply

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