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What is the difference between butane and propane?

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Propane and butane are both forms of LPG gas – but what’s the difference between the two? We’ve pulled together everything you need to know about the two gases, and how to decide which one is best suited for your needs. 

If you don’t currently use LPG and would like to know more about how you could reduce your carbon emissions by switching from oil to LPG or BioLPG, find out more here.

What is LPG?

LPG (Liquefied Petroleum Gas) is a colourless, low carbon, and highly efficient fuel which is supplied in two main forms – propane and butane. Although both propane and butane power appliances in the same way, the properties that make up the gases (and the different ways that they are extracted and stored) means that which gas you choose will depend on your needs.

What is propane?

Propane is a form of LPG which comes from natural gas processing and oil refining – the gas is liquified through pressurisation. With a low boiling point of -42°C*, propane isn’t affected by the cold conditions here in the U.K, making it ideal for outdoor use. It is stored in gas bottles or bulk LPG tanks depending on your usage requirements and preferred storage solution.

Propane is widely used for both domestic and commercial appliances. It is typically used for BBQ’s, patio heaters, LPG gas cooking, heating water, and heating your home, as well as operating tools, ovens, or forklift trucks.

What is butane?

Butane is also a form of LPG. It has a higher boiling point at -2°C, so is better suited to indoor use, and fuelling appliances like portable gas heaters and single-burner cooking stoves. Like propane, butane takes the form of a gas, so needs to be liquefied for storage. It’s typically stored in smaller canisters; for residential properties, you can store up to 30kg of butane (2 x 15kg gas bottles) indoors. Butane gas bottles are great for caravanning and camping trips when a portable and reliable gas supply is needed.

How do they compare?

The key difference between propane and butane is their boiling point. Propane can handle much lower temperatures, which is why it’s used in homes with outdoor storage. Butane, on the other hand, is better stored indoors as it doesn’t function as effectively in colder climates.

For example, here in the UK, January 2021 was the coldest January we‘d had in over a decade.***. In these conditions butane, which has a boiling point of -2°C, would not work effectively outdoors, whereas propane would.

In terms of storage, both fuels can be stored in a range of ways. You can learn more about the many storage options here, or find which gas bottle you need here.

What is the effect on your carbon emissions?

When it comes to carbon emissions, both propane and butane are clean burning fuels that are better for the environment than alternatives such as oil. If you are using propane in BioLPG form (where it is still chemically identical to LPG and compatible with all LPG products) you can reduce your carbon emissions by up to 38% when compared to oil**.

BioLPG, an eco-propane, is a renewable, sustainable energy source made from a blend of waste, residues, and sustainably sourced materials. It’s chemically identical to LPG and is compatible with all LPG products - BioLPG has no compromise on performance, so it's as energy efficient as LPG, whilst supporting us all to achieve a more sustainable future.

BioLPG can be supplied to your home as part of Calor’s Green Energy Plan, whereby 40% of your home energy is renewable (40% BioLPG / 60% LPG mix). By opting for this plan, you’re buying into a sustainable mix and a more sustainable future. The entire LPG supply industry has committed to supplying 100% renewable energy by 2040, and we’re proud to be leading the way towards meeting this ambitious target.

The benefits of propane vs butane

Below you can find the key characteristics and benefits of propane and butane broken down into a table, so you can directly compare your energy usage needs and decide which fuel is better for you:

  Propane Butane 
Characteristics Low boiling point, stored in larger quantities for residential and commercial use Higher boiling point, stored in smaller quantities for indoor use residentially or for outdoors, such as camping
Boiling Point
(when it freezes)
-42°C -2°C
Best / Ideal for BBQ’s, patio heaters, LPG gas cooking, heating water, and heating your home Portable gas heaters and single-burner cooking stoves
Gas Bottles Sizes Up to 47KG Up to 15KG
Carbon Emissions Reduce your carbon emissions by up to 38% when compared to oil** Reduce your carbon emissions by up to 38% when compared to oil**
Type Of Gas Regulator pre-set to 37mbar pre-set at 28-30 mbar

Frequently asked questions

We’ve listed some frequently asked questions below which may help you with any further queries you have around propane and butane.

Either can be used, but generally, propane is the more popular choice.
This depends largely on how many burners your gas barbeque has. If it has between one and three, a 5kg patio gas bottle is ideal. If you’ve got a larger barbeque with four burners or more, then it’s recommended that you select a 13kg bottle.
Butane regulators are pre-set at nominally 28-30 mbar and a propane regulator is pre-set to 37mbar.
Butane is ideal for indoor heaters, while with its lower boiling point, propane is better suited to outdoor storage, so can also be used for heaters. Which you choose will depend on your heating needs, and storage available.

Gas bottles are available at retailers such as Morrisons and Tesco, or you can visit our online shop for more information about gas bottles and to place your order (subject to availability).

Most appliances can be used with either butane or propane – however, they use different regulators due to the different pressures they operate at, so for example, a butane cylinder wouldn’t work with a propane regulator.
It is safe to use either butane or propane indoors, as long as you ensure you are careful, and that there is proper ventilation.
There are differences between butane and propane which could either be advantageous or disadvantageous depending on how they are being used – which gas is better will entirely depend on its use.
Butane tends to be slightly cheaper than propane, but which gas you choose should always be based on what purpose it’s to be used for, and what works with your appliances.
If used or stored incorrectly, gas canisters can explode – make sure you always carefully follow instructions for use and storage of any fuel.
Butane gas stoves are not banned in the UK.
Even when properly maintained and adjusted, gas heaters do produce low amounts of carbon monoxide – it’s essential that if using propane indoors you make sure the area is properly ventilated.