14 by 8 ft slab at 5 inches
Calculate the specifications for a 14 ft by 8 ft residential slab at 5 in thickness with #4 bars at 18 in spacing. Ensure compliance with IRC R506 standards.
Formula SSC-2026.1
Formula SSC-2026.1 · 4,000 PSI
Order volume
1.90 yd³
1.454 m³ placed+waste
Order weight
7,700 lb
3,493 kg
80 lb bags
86
3 pallets at 42 bags
60 lb bags
115
0.45 ft³ yield each
Rebar
164.00 ft
16 × 20 ft · 16 × 6 m · 121 lb
Ready-mix vs bags
$438.70
Truck $438.70 · 80 lb bags $580.50
Grid lines are equalized so the drawing stays readable. The order count uses on-center spacing with a bar at each end of the layout, then holds concrete cover in the field.
| Item | Net | Waste | Order | Unit price | Line total | Source Spec Material / Tool |
|---|---|---|---|---|---|---|
| Ready-mix concrete | 1.73 yd³ | 10% | 1.90 yd³ / 1.454 m³ | USD | $313.70 | Source Spec Material / Tool |
| Short-load fee | Under 4 yd³ | — | 1 truck @ 10 yd³ | USD | $125.00 | Source Spec Material / Tool |
| 80 lb pre-mix bags | 77.8 bags | 10% | 86 bags | USD | $580.50 | Source Spec Material / Tool |
| 60 lb pre-mix bags | 103.7 bags | 10% | 115 bags | USD | $621.00 | Source Spec Material / Tool |
| #4 rebar sticks, 20 ft | 16 sticks | 10% | 18 sticks / 16 × 6 m | USD | $252.00 | Source Spec Material / Tool |
| Rebar chairs | 60 crossings | 10% | 66 chairs | USD | $18.48 | Source Spec Material / Tool |
| Tie wire rolls | 60 ties | 10% | 1 rolls | USD | $8.00 | Source Spec Material / Tool |
Source links open a product search on the Amazon storefront for the selected currency. SiteSpecCalc may earn a commission. The link does not change the quantities above.
Ready-mix truck
$438.70
0.19 nominal 10 yd³ loads · 1 to order
80 lb bags
$580.50
60 lb alternative $621.00 · delivery weight 7,700 lb
| Thickness | Order yd³ | Order m³ | 80 lb bags | Rebar ft | Ready-mix | 80 lb cost |
|---|---|---|---|---|---|---|
| 4 in | 1.52 | 1.163 | 69 | 180 | $375.96 | $465.75 |
| 5 in | 1.90 | 1.454 | 86 | 180 | $438.70 | $580.50 |
| 6 in | 2.28 | 1.744 | 103 | 180 | $501.44 | $695.25 |
Show the deterministic formula
Slab ft³ = L × W × thickness ÷ 12. Thickened-edge extra = footing band × (footing depth − slab thickness), with corner squares counted once.
yd³ = ft³ ÷ 27. m³ = ft³ × 0.0283168. Weight uses 150 lb/ft³, then the header converts that pound total at 1 lb = 0.45359237 kg. 80 lb bags yield 0.6 ft³ and 60 lb bags yield 0.45 ft³. Currency changes the price labels only.
Bars across a span = floor(span ÷ spacing) + 1. Order sticks = that count, plus 10, 5, or 15 percent waste, cut from 20 ft and 6 m stock. Chairs = one per grid intersection.
Contractor sign-off
Project: 14 by 8 ft slab at 5 inches
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This sheet is an estimate for ordering and layout discussion. It is not a sealed design. Confirm the quantities with a licensed local professional and the authority having jurisdiction before you buy or build.
Engineering notes
This calculator assists in determining the specifications for a residential slab measuring 14 ft by 8 ft with a thickness of 5 inches. The design incorporates #4 rebar spaced at 18 inches, adhering to the guidelines set forth in IRC R506.
Please note that soil design considerations are excluded from this calculation. It is essential to consult a qualified engineer for soil analysis and site-specific requirements.
Code reference
IRC R506
Field questions
- What is the purpose of using #4 bars in the slab?
- The #4 bars provide reinforcement to the concrete slab, enhancing its tensile strength and helping to prevent cracking.
- Why is soil design excluded from this calculation?
- Soil design is site-specific and requires a geotechnical analysis to determine the appropriate foundation design based on soil conditions.
- What does IRC R506 cover?
- IRC R506 outlines the requirements for concrete slabs on grade, including thickness, reinforcement, and curing methods to ensure structural integrity.