Firewood Units: Cord, Stere, Raummeter, Festmeter and Loose m³
What each firewood unit actually contains, a conversion table between all five, and what one stere weighs — by species, dry and fresh.
What each unit actually contains
A stere (Raummeter, rm) is one cubic metre of neatly stacked split logs — air gaps included. A Festmeter (fm) is one cubic metre of solid wood with no gaps at all. A Schüttraummeter (srm, loose or bulk m³) is dumped rather than stacked, so it holds even less wood. The working rule is 1 stere ≈ 0.7 solid m³ ≈ 1.4 loose m³. One full cord is 128 stacked ft³ = 3.62 m³, about 3.6 steres.
Conversion table
Read across the row to convert one unit into the others:
| 1 unit of… | Stacked m³ (rm) | Solid m³ (fm) | Loose m³ (srm) | Stacked ft³ |
|---|---|---|---|---|
| Stere / Raummeter | 1.00 | 0.70 | 1.40 | 35.3 |
| Festmeter (solid m³) | 1.43 | 1.00 | 2.00 | 50.5 |
| Schüttraummeter (loose m³) | 0.71 | 0.50 | 1.00 | 25.2 |
| Full cord (128 ft³) | 3.62 | 2.54 | 5.07 | 128 |
| Face cord (4×8 ft × 16 in) | 1.21 | 0.85 | 1.69 | 42.7 |
Why 0.7 is a rule of thumb, not a constant
The solid fraction depends on what is in the stack. Neatly stacked, well-split hardwood reaches 0.70–0.75 solid m³ per stacked m³; coarse splits and round billets fall to 0.60–0.65; 1-metre roundwood is lower still. Log length matters too: 25 cm splits stack tighter than 33 cm ones. Loose volume follows the same logic in reverse — 1.35–1.55 loose m³ per stacked m³, higher for short pieces. If you are buying, the factor is worth agreeing on in advance; if you are calculating, adjust it in Firewood.
What a stere weighs, by species
Weight = stacked volume × solid fraction × density, so one stere of dry beech is 1 × 0.7 × 720 = 504 kg — not 720 kg, which is what a solid cubic metre would weigh:
| Species | kg/m³ solid | kg per stere (dry) | kg per stere (fresh) | kWh per stere |
|---|---|---|---|---|
| Spruce | 450 | 315 | 473 | ~1,290 |
| Fir | 480 | 336 | 504 | ~1,380 |
| Pine | 500 | 350 | 525 | ~1,440 |
| Poplar | 420 | 294 | 441 | ~1,210 |
| Birch | 620 | 434 | 651 | ~1,780 |
| Ash | 700 | 490 | 735 | ~2,010 |
| Beech | 720 | 504 | 756 | ~2,070 |
| Red oak | 750 | 525 | 788 | ~2,150 |
| White oak | 770 | 539 | 809 | ~2,210 |
Buying firewood without getting the unit wrong
Four questions settle almost every dispute: which unit is being quoted (rm, srm or fm — a price per srm looks 30% cheaper than the same wood per rm), what log length, what moisture content, and which species. Firewood should be at or below 20% moisture before it is burned; above that a large share of the energy goes into evaporating water and into the chimney. Check it with a meter, or estimate the drying with the Moisture content and EMC calculators.
Convert your own load
Enter any quantity in Firewood and it returns every other unit at once — steres, cords, solid m³, loose m³ and stacked ft³ — plus the weight for the species you pick, dry or fresh. For sawn timber rather than firewood, Timber unit converter handles m³, board feet, MBF and Hoppus, and Lumber weight calculator gives the weight of a specific board.