Fire Load Calculator

Calculates total fire load and fire load density (MJ/m²) from combustible material inventory, per the method in EN 1991-1-2 (Eurocode 1, Actions on Structures Exposed to Fire), Annex E.

Combustible Materials

Compartment & Combustion Factor

Floor Area (m²)

Combustion Factor, m EN 1991-1-2 recommends 0.8 for cellulosic materials, 1.0 for liquid fuels (complete combustion assumed).

0 MJ

Total Fire Load

0 MJ/m²

Fire Load Density

Formula Reference

Total Fire Load = Σ (Mass × Calorific Value) × Combustion Factor (m)
Fire Load Density (qf) = Total Fire Load ÷ Floor Area [MJ/m²]

Typical Net Calorific Values

Wood	~17.5 MJ/kg
Paper / Cardboard	~16.5 MJ/kg
Textiles / Fabric	~20 MJ/kg
Plastics (general)	~35 MJ/kg (varies 17–46 by polymer type)
Rubber	~32 MJ/kg
Foam / Polyurethane	~35 MJ/kg
Hydrocarbon liquids	~44 MJ/kg

Typical Occupancy Fire Load Density (reference only)

Office (80% fractile, EN 1991-1-2)	~511 MJ/m²
Dwelling / Residential	~500–780 MJ/m²
Retail / Shop	~600–1,000 MJ/m²
Storage / Warehouse	often > 1,000 MJ/m² — highly variable by stored goods

These occupancy figures are general references compiled from Eurocode and industry fire-load surveys — actual values vary significantly by building, storage density, and country. Use your own compartment survey as the primary basis for design.

Based on the fire load density methodology in EN 1991-1-2 (Eurocode 1), Annex E. This is a screening-level calculation — the design fire load density (qf,d) used in formal structural fire engineering also applies additional factors for fire risk (activation, fire-fighting measures, compartment size) beyond the basic combustion factor shown here. For statutory approval, insurance submission, or structural fire resistance design, a competent fire engineer should verify material inventory, calorific values, and all applicable design factors. For customized calculators tailored to your organization, please contact Impact Tech Solutions.