Building Material Weight Calculator

Weight is calculated in three steps: (1) Volume = length × width × height [m³]; (2) Mass = volume × density [kg]; (3) Gravitational weight = mass × 9.81 / 1000 [kN]. This applies to any homogeneous material with a known density.

Ordinary plain concrete has a density of approximately 2300–2400 kg/m³. Reinforced concrete (with steel rebar) is typically 2400–2500 kg/m³. Lightweight concrete can be as low as 1200 kg/m³, while high-density concrete reaches 3000 kg/m³.

Structural steel has a standard density of 7850 kg/m³ (commonly rounded to 7800 kg/m³). This applies to carbon steel, mild steel, rebar and most structural sections. Stainless steel is slightly denser at around 7900–8000 kg/m³.

The density of wood varies significantly by species and moisture content. Air-dried softwood (pine, spruce) is typically 500–600 kg/m³, while hardwood (oak, beech) ranges from 650–900 kg/m³. Wet or green timber is considerably heavier. Use the actual density for your timber species when precision is required.

A solid clay brick has a density of around 1800 kg/m³, so 1 m³ of solid brickwork weighs approximately 1700–1900 kg including mortar joints. Hollow or perforated bricks reduce this to 1300–1600 kg/m³. Always check the manufacturer's data sheet for the specific product.

Mass is measured in kilograms (kg) and represents the amount of matter in an object — it does not change with location. Weight is a force measured in newtons (N) or kilonewtons (kN) and equals mass × gravitational acceleration (9.81 m/s²). Structural loads are usually expressed in kN or kN/m², while transport and purchasing use kg or tonnes.

The standard gravitational acceleration on Earth's surface is 9.80665 m/s², rounded to 9.81 for engineering purposes. Eurocode and Polish structural norms (PN-EN 1990) use this value for converting mass to force. In some older Polish standards 9.81 m/s² or even 10 m/s² (a conservative approximation) is used.

Use the same formula: volume × density. Dry sand has a density of approximately 1500–1700 kg/m³ and moist sand 1800–1900 kg/m³. For a loose heap, measure or estimate the volume carefully — a cone-shaped pile has volume = (π × r² × h) / 3. Enter the calculated volume as length × width × height approximation or use the total volume directly.

Standard steel sections have published linear mass (kg/m) in manufacturer tables and Eurocode tables (EN 10365). For example, an IPE 200 beam weighs 22.4 kg/m, an HEA 200 weighs 42.3 kg/m. Multiply by the length to get total mass. The calculator handles rectangular solids — for complex profiles use manufacturer tables.

The calculator provides accurate mathematical results for the given inputs. Accuracy depends primarily on the density value you enter — real materials may deviate ±5–10% from tabulated values due to moisture, additives, and production tolerances. For structural design, always verify with certified material data and consult a licensed engineer.