Stowage factor is the single most useful number in cargo planning: it tells you how much volume a tonne of cargo will occupy once it is loaded and trimmed. This tool gives you a searchable table of typical factors for common bulk, break-bulk, and bagged commodities, converts between metric and imperial units, and works out whether a given hold will be space-limited or weight-limited.
How it works
The stowage factor (SF) already includes broken stowage, so the volume a parcel occupies is simply mass multiplied by SF. Two limits decide how much you can load:
mass that fills the hold by volume = hold volume (m3) / SF (m3/MT)
loadable cargo = min(volume-limited mass, deadweight available)
volume utilisation = (loadable × SF) / hold volumeIf the deadweight available is the smaller number, the parcel is weight-limited
and space is left over. If the volume-limited mass is smaller, the hold fills up
before you reach the deadweight. The imperial equivalent is found by multiplying
the metric SF by 35.8814.
Reference stowage factors for common cargoes
These are approximate mid-range figures for planning. Actual factors vary with moisture content, packaging, trimming, and temperature:
| Cargo | Typical SF (m3/MT) | Notes |
|---|---|---|
| Iron ore | 0.30–0.40 | Always weight-limited; very dense |
| Coal (bituminous) | 0.80–1.20 | Moisture content affects density |
| Grain (wheat/corn) | 1.20–1.45 | Space-limited in typical bulk carriers |
| Bagged rice | 1.60–1.80 | Broken stowage adds vs bulk |
| Sugar (raw, bulk) | 0.90–1.15 | Shifts in water; check stability |
| Cement (bulk) | 0.65–0.80 | Absorbs moisture; requires segregation |
| Fertiliser (granular) | 0.85–1.10 | Corrosive; tank top protection needed |
| Timber (logs) | 1.60–2.40 | High broken stowage; varies enormously |
| Cotton (baled) | 2.00–3.00 | Very space-hungry; fire risk |
| Steel coils | 0.20–0.30 | Almost always weight-limited |
| Container (20ft, full) | ~1.15 | Approximate; TEU planning uses capacity tables |
Full and down: the key concept
A ship is “full and down” when a hold simultaneously reaches its cubic capacity and its deadweight capacity at the same time. In practice most cargo types are either consistently space-limiting or consistently weight-limiting:
- Dense cargoes (ore, steel, sugar): The hold’s deadweight is reached long before the cubic is full. The hold is “down” (maximum draught) with space remaining. Adding more cargo would be structurally unsafe.
- Light cargoes (timber, cotton, grain at high stowage factors): The cubic fills before the ship reaches its marks. The hold is “full” with deadweight remaining. Forcing more weight in is impossible once the hold is physically full.
Understanding which limit applies helps cargo officers and chartering managers plan the correct number of holds to open, the stowage sequence, and ballasting requirements.
Worked examples
Wheat in a 10,000 m³ hold, 8,000 MT deadweight available:
Volume-limited mass = 10,000 / 1.30 ≈ 7,692 MT
Deadweight available = 8,000 MT
Loadable cargo = min(7,692, 8,000) = 7,692 MT → space-limited
Volume utilisation = (7,692 × 1.30) / 10,000 = 100%The hold goes full at 7,692 MT, leaving 308 MT of unused deadweight.
Iron ore in the same hold:
Volume-limited mass = 10,000 / 0.35 ≈ 28,571 MT
Deadweight available = 8,000 MT
Loadable cargo = min(28,571, 8,000) = 8,000 MT → weight-limited
Volume utilisation = (8,000 × 0.35) / 10,000 = 28%The ship reaches its marks at 8,000 MT with 72% of the hold volume empty. This is typical for ore: large holds carry much less than their cubic would suggest.
Always use the actual stowage factor from the cargo declaration for a fixture, not the table estimate — moisture, packing, and trim make a measurable difference, particularly for cargoes near their angle of repose or those prone to compaction.