How much does it cost to run a gas fireplace?

You love the idea of a gas fireplace – real flames, instant warmth, no firewood to stack – but you want to know what it'll actually add to your gas bill before you commit. Fair enough.

The short answer: most gas log fires cost between $0.70 and $1.80 per hour to run on natural gas. Where you land in that range depends on the size of the fireplace, how much your gas costs per megajoule, and how long you run it each day. Here's how to work out what it would cost in your home.

What affects how much your gas fireplace costs to run?

Four things drive the running cost of a gas fireplace. Understanding each one helps you estimate your costs before you buy – and control them once the fireplace is installed.

The fireplace’s MJ/h rating. Every gas fireplace has a megajoule-per-hour (MJ/h) rating. This tells you how much gas the unit uses each hour at full output. A smaller decorative model might use 15–20 MJ/h. A standard gas log fire designed to heat a living area typically uses 25–35 MJ/h. A larger unit heating 100-plus square metres can use 40 MJ/h or more. The higher the MJ/h, the more gas it burns – but also the more heat it puts out. If you’re not sure how to match a fireplace size to your room, our guide to choosing the right size gas heater breaks down the relationship between MJ/h input and kW heat output.

Your gas rate. Gas prices in Australia vary by state. Victorian households typically pay around 3.5 to 4 cents per MJ – one of the lowest rates in the country. In New South Wales, expect 3.5 to 4.5 cents per MJ. South Australian rates sit higher at around 5 to 5.5 cents per MJ. That difference adds up over a winter season, so it’s worth checking your latest gas bill for your actual rate.

How many hours you run it. Most households use their gas fireplace for three to five hours on a cold evening. Running a fireplace for two hours on a mild night costs half as much as running it for six hours during a cold snap. This sounds obvious, but it’s the single biggest variable in your seasonal bill.

Natural gas vs LPG. If your home is connected to mains natural gas, the costs above apply. If you’re on LPG (bottled gas) – common in regional areas without mains gas – running costs are significantly higher. LPG can cost two to three times more per MJ than natural gas. If you’re on LPG and considering a gas fireplace, factor this into your budget or ask about electric fireplace options as an alternative.

How much does a gas fireplace cost per hour, per day, and per season?

Here’s what typical running costs look like across three common fireplace sizes, based on a Victorian gas rate of 3.5 cents per MJ and four hours of use per day.

	Small (~20 MJ/h)	Medium (~30 MJ/h)	Large (~40 MJ/h)
Cost per hour	~$0.70	~$1.05	~$1.40
Cost per day (4 hrs)	~$2.80	~$4.20	~$5.60
Cost per month	~$84	~$126	~$168
Cost per season (4 months)	~$336	~$504	~$672

If you’re in South Australia or another state with higher gas rates, add roughly 30–50% to these figures. A medium unit running at 5 cents per MJ, for example, would cost closer to $1.50 per hour rather than $1.05.

One thing worth noting: these figures cover gas usage only. Your gas bill also includes a daily supply charge for being connected to the gas network, but that applies to your household connection regardless of whether you have a gas fireplace. Running a gas fireplace doesn’t add a new supply charge – it only adds the gas you actually burn.

How does a gas fireplace compare to other heating on running cost?

Running cost is one part of the picture. What you get for that cost matters just as much.

Gas fireplace vs electric fireplace. An electric fireplace typically costs around $0.50 to $0.70 per hour to run at 2 kW – less per hour than most gas fireplaces. But electric units deliver around 2 kW of heat, while a gas log fire delivers 5–6 kW or more. For a large living area or open-plan space, a gas fireplace heats the room faster and more thoroughly. For a smaller room or apartment, an electric fireplace may be all you need. If you’re weighing up the two, our guide to whether electric fireplaces are worth it covers the comparison in detail.

Gas fireplace vs reverse cycle. A reverse cycle air conditioner is typically the cheapest option per kilowatt of heat, because it moves heat from outside rather than generating it from fuel. But a gas fireplace offers something a reverse cycle can’t – real flame ambience, radiant warmth, and a focal point in the room. Many households use both: reverse cycle for general background heating and a gas fireplace in the main living area for comfort and atmosphere on cold evenings.

Gas fireplace vs wood heater. A wood heater can be cheaper to run if you have access to free or low-cost firewood. But gas wins on convenience – instant on and off, no ash, no firewood storage, and no flue cleaning. Gas also burns cleaner, with no wood smoke to manage.

How can you keep your gas fireplace running costs down?

A few practical steps can keep your gas bill lower without sacrificing comfort.

• Right-size the fireplace to your room. An oversized unit burns more gas than you need. A unit matched to your room size runs more efficiently and heats the space just as well.
• Use the thermostat. Modern gas fireplaces have built-in thermostats that adjust the flame height and gas flow automatically. Once the room reaches your set temperature, the fireplace dials back rather than running at full output all evening.
• Heat the room you’re in. One of the biggest advantages of a gas fireplace is zone heating – warming the living area you’re actually using rather than heating the whole house. This is almost always cheaper than running ducted heating throughout a home.
• Keep up with annual servicing. A well-maintained gas fireplace runs more efficiently than a neglected one. Dirty burners, blocked vents, or worn seals can all increase gas consumption. If your fireplace hasn’t been serviced recently, our pre-season checklist covers what to check before winter.
• Improve your room’s insulation. Draught-proofing windows and doors, closing off unused rooms, and even using heavy curtains can reduce how hard your fireplace has to work – and how long you need to run it.

Is a gas fireplace expensive to run compared to the comfort it provides?

For most Victorian households, a gas fireplace running four hours a day through winter adds roughly $120 to $170 per month to the gas bill. Over a four-month winter season, that’s $500 to $670 in total running costs.

What you get for that is real flame heating in your main living area – instant warmth when you switch it on, no firewood to split or store, no ash to clean out, and no smoke to worry about. For families spending their evenings in the living room through Melbourne’s colder months, that’s a meaningful upgrade in daily comfort for a manageable running cost.

The best way to pin down what a specific model would cost in your home is to visit one of Illusion Fires’ showrooms – in Dandenong, Epping, Geelong, Ballarat, Adelaide, Perth, Sydney, or Newcastle. You can see gas fireplaces running, compare models side by side, and ask about the MJ/h rating and expected running cost for any unit you’re considering.

Frequently asked questions

Does a gas fireplace use a lot of gas?
It depends on the model. A smaller gas log fire uses around 15–20 MJ/h, which is modest. A larger unit heating a big living area might use 40 MJ/h or more. For context, a standard gas cooktop burner uses about 12–15 MJ/h – so a medium gas fireplace is roughly equivalent to running two stovetop burners.

Is it cheaper to run a gas fireplace or a reverse cycle heater?
On running cost alone, reverse cycle is typically cheaper per kilowatt of heat produced. But many households choose a gas fireplace for the ambience, radiant warmth, and visual appeal that a reverse cycle unit doesn’t provide. The two work well together – reverse cycle for general heating, gas fireplace for comfort in the main living area.

How much does it cost to run a gas fireplace per hour in Victoria?
At Victorian gas rates of around 3.5 cents per MJ, a typical gas log fire costs between $0.70 and $1.40 per hour depending on the model’s MJ/h rating and flame setting.

Does leaving the pilot light on cost money?
Yes, but not much. A pilot light uses a small amount of gas continuously – typically around 1–2 MJ/h. At Victorian rates, that works out to around $1 to $2 per day. Some newer models use electronic ignition instead of a standing pilot, which removes this cost entirely.

Is LPG or natural gas cheaper for a gas fireplace?
Natural gas is significantly cheaper. LPG can cost two to three times more per megajoule than mains natural gas. If your home doesn’t have a natural gas connection, it’s worth comparing the total running cost of an LPG gas fireplace against an electric fireplace before you decide.