Dead Load vs Live Load
Compare permanent and variable loads, understand their sources, and see how they influence structural sizing.
Two Core Load Categories
Design standards split loads into dead loads (permanent) and live loads (variable). Understanding the difference keeps calculations organized and prevents underestimated forces.
Dead Loads
- Self-weight of concrete, steel, wood members
- Permanent partitions, finishes, built-ins
- Roofing, cladding, mechanical systems
Live Loads
- People, furniture, movable equipment
- Vehicles, storage pallets, temporary machinery
- Any usage-driven load that can appear or disappear
Why the Distinction Matters
- Dead loads rarely change, so they anchor the baseline for structural sizing.
- Live loads fluctuate, so ASCE 7 supplies default values based on occupancy.
- Combining both with environmental effects ensures conservative design.
Using Calculators
When you estimate slab or foundation size, start with approximate dead load from materials, then layer in the governing live load category. Online calculators give quick quantities, but the final selection of load values must match local code tables.
Try the Calculator
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