Floor Loads – Dead + Live by Occupancy

Quick answer

Floor load check: dead 1.5-5 kN/m² (finishes+slab), live 2.0 residential to 5.0 retail and offices per code tables - deflection L/360 live.

Figures are estimates from this calculator’s standard formula — adjust the inputs in the tool below for your exact number.

How does the floor loads calculator work?

Design Load = Dead + Live (kN/m²); Deflection ≤ L ÷ 360 (live)

A reliable floor loads takeoff follows one rule: measure twice, order once. The calculator converts your occupancy type and floor system into dependable quantities using Design Load = Dead + Live (kN/m²); Deflection ≤ L ÷ 360 (live), then adds the waste margin that experienced builders apply by default. Example: Office floor: 1.0 finish + 2.5 slab self + 3.0 live = 6.5 kN/m² - a 6 m joist span carries 39 kN/m line. Field tip: Tile and screed add 1.0-1.5 kN/m² dead - the forgotten load that sags older renovations. The result is broken down into purchasable units - bags, sheets, rolls or truck loads - so you can order the nearest whole unit without overbuying, and every figure traces back to the formula shown above.

1
Take dimensions
Note the occupancy type and floor system for the area you are covering or filling.
2
Run the calculation
The calculator applies Design Load = Dead + Live (kN/m²); Deflection ≤ L ÷ 360 (live) the moment you type.
3
Check the breakdown
Compare base quantity and waste-adjusted totals side by side.
4
Plan the purchase
Use the final figure to price and schedule the delivery.

Use Cases

Electrical conduit fill

NEC 40% fill checks for floor loads wire pulls.

Scaffold planning

Bay, lift and tie counts for compliant floor loads.

Anchor and embed setting

Spacing and edge distances for floor loads baseplates.

Common Mistakes

Mixing pipe standards
Underestimating bends
Skipping scaffold ties

FAQs

Live load for residential floors?

2.0 kN/m² (40 psf) dwellings, 3.0 balconies and stairs - libraries and storage run 5.0+.

Dead load of common floor builds?

Timber joists + boards ≈ 0.8; 120 mm slab ≈ 3.0; +50 mm screed and tile ≈ +1.2 kN/m².

Safe point load from a safe or piano?

A 400 kg piano over 0.25 m² = 16 kN/m² locally - spread heavy items on pads and place them near walls.

Deflection limit for floors?

L/360 under live load, L/240 total - tile floors want L/480 or the grout cracks.

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