Stacked vs Loose Volume: What You Need to Know When Buying Firewood
Updated: Nic SnellWhen it comes to buying firewood, understanding the difference between stacked and loose-filled volumes is essential, especially if you're trying to compare suppliers or check that you’re getting good value. At Certainly Wood, we believe in complete transparency, and that includes helping our customers make informed decisions when it comes to volume, pricing, and how our kiln-dried firewood is packed.
So, what’s the difference between loose firewood and stacked logs, and why does it matter?
An Overview: Loose vs Stacked Volume
According to data from the Wood Fuels Handbook published by the Food and Agriculture Organisation of the United Nations, this is the method to help work out the conversion between stacked and loose-filled volumes: 1m3 stacked volume (crate) = 1.67m3 loose fill volume.Certainly Wood Firewood Conversions
Crates:
| Medium | Large | Extra Large | |
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Internal Dimensions: 5% tolerance |
W115cm, D108cm, H69cm | W115cm, D108cm, H111cm | W115cm, D108cm, H149cm |
| Loose Volume (approx) | 1.42m3 | 2.29m3 | 3.08m3 |
| Stacked Volume (approx) | 0.85m3 | 1.37m3 | 1.84m3 |
Bulk Bags:
| Large | Extra Large | |
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Bag Dimensions |
W110cm, D110cm, H115cm | W110cm, D110cm, H150cm |
| Loose Volume (approx) | 1.2m3 | 1.6m3 |
| Stacked Volume (approx) | 0.72m3 | 0.96m3 |
What Is Loose Volume?
Loose-filled volume means the logs are loaded into a bag or container without any stacking; they fall naturally, creating air gaps between them. This is the most common measurement used for bulk bags across the firewood industry.
Because of the air gaps, a loose-filled bag will look fuller but contain fewer logs than the same volume of stacked logs.
What Is Stacked Volume?
Stacked volume refers to logs that are neatly arranged, with each log stacked to minimise empty space. It’s a denser way to pack wood, offering a clearer visual reference for how much you’re getting.
At Certainly Wood:
- Our crates, as well as our small bags and boot bags, are all stacked by hand.
- This ensures consistency in volume and helps with cleaner storage and handling once delivered.
How to measure stacked & loose volumes
| Stacked Volume |
Loose Volume |
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Stacked volume refers to the space taken up by the firewood itself, with the logs neatly arranged and tightly packed. We calculate this using the approximate internal dimensions of the crate (height × width × depth). The tighter the stack, the more wood you receive per cubic metre. 👉 At Certainly Wood, our crates, small bags, and boot bags are all measured by stacked volume to give you a clear, consistent view of how much firewood you’re getting.
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Loose volume refers to firewood that’s tipped, with logs falling naturally into a bag or container. This creates extra air gaps between the logs. As a general industry guide, loose-filled volume is around 67% larger than the same stack when measured neatly.
👉 For example, our 1.2m³ bulk bag, measured as a loose-filled volume, would equate to around 0.72m³ when stacked (1.2 ÷ 1.67 = ~0.72m³).
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Why do we quote firewood in volume?
It was traditional to buy wood by the ‘tonne’ or ‘load’, but now that firewood is mostly kiln dried, it is more relevant to supply wood by volume. The drier the wood, the higher its heat value, but it will be much lighter than fresh or semi-seasoned wood. Buying a tonne of wood could suggest a heavier load at the same price, but you may be paying for water. As a general rule, the heavier the wood, the higher the moisture content, although also consider that oak, for example, is heavier than silver birch.