The Stere: Cubic-Metre Volume Unit for Stacked Firewood
A stere (symbol st) is defined as one cubic metre (1 m³) of stacked firewood, including void spaces between logs. The unit originated in 18th-century France to standardize fuelwood trade after adoption of the metric system. Unlike loose cubic metres, the stere assumes pieces are neatly stacked, yielding predictable packing density for billing and transport.
Because 1 stere equals 1,000 litres, traders can convert between stere, litres, and other units such as the litre or the traditional cord (≈3.62 stere). This makes it easy to integrate stere-based inventories into digital logistics platforms.
Definition and Measurement
Stack geometry
A typical stere stack measures one metre high, one metre deep, and one metre long. Logs are usually cut to 1 m or 0.5 m lengths to fit stoves and trailers. Because stacking efficiency varies with log diameter and bark roughness, suppliers often note whether volumes are expressed as “stere stacked” or “stere loose.”
Converting to mass
To calculate energy content, operators multiply the stere volume by wood bulk density (kg/m³) and higher-heating-value data. Referencing the bulk-density article ensures consistent assumptions across species and moisture levels.
Accounting for moisture
Moisture content strongly influences weight and burning performance. Suppliers often advertise “stere of seasoned hardwood at 20% moisture,” signalling that the measured stack has equilibrated in air for at least one summer.
Historical Development
Metric reforms in France
The stere debuted alongside the metric system in 1795, providing a simple volume unit for firewood analogous to the metre for length and kilogram for mass. Its adoption simplified taxation and standardized military supply during the Napoleonic era.
Spread across Europe
Many continental countries embraced the stere for forestry and district heating markets. While Anglophone regions retained the cord, international trade increasingly quotes both units to avoid ambiguity.
Modern regulations
EU consumer-protection laws require retailers to state whether advertised volumes are in stere or loose cubic metres. Truck scales and volumetric scanners verify that shipments match invoiced quantities.
Conceptual Considerations
Packing efficiency and air gaps
The stere explicitly includes void space. Softwoods with uniform diameters pack more efficiently than mixed hardwood loads, so the delivered energy per stere can vary by ±15%. Customers may specify “resplit” loads to improve packing and reduce voids.
Logistics and freight
Converting stere volumes to freight dimensions helps determine how many stacks fit on a trailer. Tools like the triangular-prism volume calculator assist when piles are wedge-shaped or stored against walls.
Comparisons with other volume units
Bulk commodities often use sector-specific units—hogsheads in brewing, register tons in shipping. Linking stere measurements to the gross-register-tonnage article or to tools like the hogshead converter keeps reporting interoperable.
Applications
District heating and biomass markets
Municipal heating plants procure fuelwood by the stere to match boiler charging systems and storage silos sized in cubic metres. Contracts specify acceptable species mixes, moisture, and kappa-based chemical content when pulp chips are diverted.
Retail firewood and e-commerce
Online marketplaces list prices per stere or per half-stere, often bundled with delivery distances. Sellers provide photos of stacked loads alongside volumetric measurements to maintain trust.
Freight pricing and carbon accounting
Carriers may charge by volumetric weight rather than mass. Using the volumetric-weight calculator helps shippers anticipate surcharges and plan pallet configurations. Carbon accounting frameworks also convert stere volumes to tonnes of CO₂ stored in harvested wood products.
Importance and Communication
Consumer transparency
Publishing stere-based price lists reduces disputes between suppliers and homeowners accustomed to cords or truckloads. Visual aids showing 1×1×1 m stacks reinforce the definition.
Integration with digital supply chains
Inventory software tracks stere balances alongside other units, ensuring compatibility with enterprise resource planning systems and customs documentation. Linking stere entries to litre conversions and density tables simplifies export paperwork.
As bioenergy, outdoor living, and artisanal heating markets grow, the stere remains a practical bridge between historic fuelwood trade and modern logistics.