Buying firewood by the tonne or cubic metre: what should you know?
A firewood offer sold “by the metre” can look much cheaper than firewood sold by the tonne. But are you actually comparing the same amount of timber? Here is what weight, volume, loose-filled cages, timber density and moisture mean when comparing firewood.
How many cubic metres are in one tonne of firewood?
There is no fixed conversion. A tonne measures weight and a cubic metre measures volume. Timber density, moisture, split size and the amount of air between pieces can all change the relationship. For customers wanting a rough planning guide, our typical firewood has historically been around 2.0m³ per tonne for Red Gum and around 2.4m³ per tonne for Blue Gum when considered as stacked firewood. These figures are approximate only — our bulk firewood is sold by measured weight, not by an assumed cubic-metre conversion.
Why buying firewood can be confusing
Search for firewood online and you will see plenty of different descriptions: tonnes, half tonnes, cubic metres, trailer loads, truck loads, IBC cages, bags and stacks.
That makes comparing price surprisingly difficult. One supplier might advertise a price per tonne while another advertises a price per cubic metre or cage. At first glance, the lower number can look like the obvious bargain.
But a tonne and a cubic metre measure completely different things. A tonne tells you the weight of the timber. A cubic metre tells you the volume it occupies.
Under Australian trade measurement rules, firewood can be sold by weight, volume or lot.
Sold by weight
Firewood sold by weight is measured in kilograms or tonnes. The advertised quantity refers to the net weight of the wood.
Sold by volume
Firewood sold by volume is measured in cubic metres. NMI guidance says the firewood should be neatly stacked with as few gaps as possible when its volume is measured.
Sold by the lot
Firewood may also be sold as a defined stack, trailer, cage or truck load. A defined lot should not automatically be assumed to represent a particular weight or cubic-metre volume.
A container that is approximately one cubic metre in external size is not automatically the same thing as one measured cubic metre of firewood.
Why can firewood sold “by the metre” look cheaper?
This is one of the biggest traps when comparing firewood prices. The amount of air between the pieces can dramatically change how large a load appears.
Imagine split firewood carefully stacked into a measured space. The pieces sit relatively closely together and there is less empty air between them.
Now take those same pieces and drop them loosely into an IBC cage, bin or trailer. The timber lands at different angles, larger gaps form between pieces, and the pile occupies more space.
The wood hasn't magically increased — the amount of air between the pieces has.
Neatly stacked firewood
Pieces are arranged closely together. This is the basis used when measuring firewood sold by cubic metre under NMI guidance.
Loose-filled cage or container
Timber dropped loosely into a cage can contain more gaps and therefore less actual wood within the same external container dimensions.
So is that cheaper “cubic metre” actually cheaper?
Maybe — but you cannot know from the advertised dollar figure alone.
If you see firewood advertised in an IBC cage or other container, ask whether the advertised quantity is a properly measured cubic metre of neatly stacked firewood, or whether you are simply buying that particular cage or load.
Two offers carrying the word “metre” can represent quite different amounts of actual timber if they have been measured differently.
But roughly, how much stacked firewood is in a tonne?
This is the question most customers actually want answered. Official guidance quite correctly warns that there is no universal conversion between weight and volume because species, density, moisture and stacking all vary.
But we also understand that if you are comparing a tonne price with somebody else's cubic-metre price, you need at least a rough sense of scale.
Based on the typical split hardwood we handle, our practical planning guide is approximately:
Our rough planning guide
Approximate stacked volume only — not a guaranteed conversion.
Why is Blue Gum different from Red Gum?
Different timber species can have different densities. That means the same tonne of one species may occupy a different amount of physical space from a tonne of another.
This is exactly why a single statement such as “one tonne equals two cubic metres” should not be treated as a universal firewood conversion.
If one supplier advertises by tonne and another advertises by cubic metre, first establish how each quantity is measured. Then consider timber species, seasoning, delivery cost and the total amount of usable firewood you are receiving.
Moisture matters whichever way you buy
Weight provides a clear quantity, but weight alone does not tell you everything about firewood quality.
Fresh or green timber contains more water than seasoned timber. That water adds weight while also making the wood harder to ignite and less suitable for efficient immediate burning.
So even when comparing suppliers selling by weight, it makes sense to ask whether the timber is seasoned and suitable for the way you intend to use it.
A useful comparison considers how the firewood is measured, the timber species, its condition and seasoning, delivery cost and whether the pieces suit your heater or fireplace.
Six questions to ask when comparing firewood
A low advertised price does not necessarily mean poor value — and a high price does not necessarily mean good value. Get the information needed to compare the offers properly.
Is it measured weight, measured stacked cubic metres, a bag, or simply a cage, trailer or truck load?
Ask whether the timber was neatly stacked for measurement or simply loose-filled into a container.
Know whether you are comparing Red Gum, Blue Gum, mixed hardwood or another timber.
If you need to burn it now, ask whether the firewood is suitable for immediate use.
Compare the complete delivered cost rather than only the advertised firewood price.
Victorian Government guidance recommends asking sellers where their firewood has been sourced.
How we sell our bulk firewood
Our current bulk hardwood range includes Red Gum, Blue Gum and a 50/50 Red Gum & Blue Gum mix, with tonne and half-tonne options available online.
Red Gum Firewood
Our traditional Red Gum option for customers wanting hardwood firewood for home heating and fireplaces.
Shop Red Gum
Blue Gum Firewood
Another hardwood option in our current bulk range, available in tonne and half-tonne quantities.
Shop Blue Gum
50/50 Red Gum & Blue Gum
A mixed hardwood option combining Red Gum and Blue Gum in one bulk order.
Shop 50/50 MixFirewood delivered across the Dandenong Ranges & the Hills
We supply and deliver firewood from Upper Beaconsfield across our local Hills, eastern Dandenong Ranges, Casey foothills and nearby Cardinia communities.
Our current bulk Red Gum, Blue Gum and 50/50 products are sold in tonne and half-tonne quantities.
Tell us about gates, access, tipping location and any requested delivery window when ordering.
Our delivery system uses SMS messaging to help keep customers informed as their order progresses.
What the official measurement guidance says
Australia's National Measurement Institute regulates trade measurement requirements for firewood. It confirms that firewood can be sold by weight, volume or lot.
When firewood is sold by cubic metre, NMI says it should be neatly stacked with as few gaps as possible when measured. NMI also cautions against assuming a fixed conversion between a measured weight and measured volume because wood density, moisture and free space can vary.
Read the official National Measurement Institute guidance on selling firewood .
Victorian Government advice also recommends asking a seller where their timber has come from, getting a proper receipt and questioning offers that appear unusually cheap. You can read the Victorian Government buying firewood guidance .
Frequently asked questions
How many cubic metres are in a tonne of firewood?
There is no universal conversion because timber density, moisture, piece size and stacking all affect volume. As a rough planning guide based on the typical firewood we handle, Red Gum is often around 2.0m³ per tonne and Blue Gum around 2.4m³ per tonne when considered as stacked firewood. These figures are approximate only. Our bulk firewood is sold by measured weight rather than by this estimated conversion.
Does a one cubic metre IBC cage contain one cubic metre of firewood?
Not necessarily. The external dimensions of a cage do not automatically establish the measured volume of the firewood inside it. Loose-filled timber can contain substantial empty space between pieces. If firewood is being advertised as a cubic-metre quantity, ask how that volume was measured.
Why can loose firewood look like more than stacked firewood?
Pieces dropped loosely into a cage, trailer or pile land at different angles and create larger spaces between pieces. Neatly stacking the same timber removes much of that empty space, so its overall occupied volume can be smaller even though the amount of actual timber has not changed.
Is buying firewood by the tonne better than buying by cubic metre?
Both are legitimate ways to sell firewood when measured correctly. Weight gives you a measured mass of timber while cubic metres give you a measured volume. The important thing is knowing what has actually been measured so that you can make a fair comparison.
Why does a tonne of Blue Gum take up more space than Red Gum?
Timber species can have different densities, so equal weights do not necessarily occupy equal volumes. This is one reason we use different rough planning estimates for Red Gum and Blue Gum rather than claiming one universal tonne-to-volume conversion.
Is heavier firewood always better?
No. Weight can be affected by timber density and moisture. Wood containing more moisture can weigh more while being less suitable for efficient immediate burning. Quantity and wood condition should be considered together.
What should I ask a firewood supplier before buying?
Ask what species you are buying, how the quantity is measured, how a cubic-metre quantity was established if one is being advertised, whether the timber is seasoned, where it was sourced and what the total delivered price will be.
Does Upper Beaconsfield General Store sell firewood by weight?
Yes. Our current bulk Red Gum, Blue Gum and 50/50 Red Gum & Blue Gum products include tonne and half-tonne ordering options. Selected bagged firewood, kindling and firelighting products are also available through our Firewood collection.
Do you deliver firewood?
Yes. We provide local firewood delivery from Upper Beaconsfield across the Dandenong Ranges, the Hills and surrounding areas. Visit our Firewood Supply & Delivery page for current delivery information.
Compare the wood — not just the advertised number
Shop Red Gum, Blue Gum, our 50/50 hardwood mix, kindling and firelighting products online, with local firewood delivery from Upper Beaconsfield across the Hills and surrounding areas.