14 by 8 ft slab at 8 inches
Calculate the specifications for a 14 ft by 8 ft residential slab at 8 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
3.59 yd³
2.741 m³ placed+waste
Order weight
14,520 lb
6,586 kg
80 lb bags
162
4 pallets at 42 bags
60 lb bags
216
0.45 ft³ yield each
Rebar
252.00 ft
22 × 20 ft · 22 × 6 m · 185 lb
Ready-mix vs bags
$716.56
Truck $716.56 · 80 lb bags $1,093.50
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 | 3.26 yd³ | 10% | 3.59 yd³ / 2.741 m³ | USD | $591.56 | 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 | 146.7 bags | 10% | 162 bags | USD | $1,093.50 | Source Spec Material / Tool |
| 60 lb pre-mix bags | 195.6 bags | 10% | 216 bags | USD | $1,166.40 | Source Spec Material / Tool |
| #4 rebar sticks, 20 ft | 22 sticks | 10% | 25 sticks / 22 × 6 m | USD | $350.00 | 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
$716.56
0.36 nominal 10 yd³ loads · 1 to order
80 lb bags
$1,093.50
60 lb alternative $1,166.40 · delivery weight 14,520 lb
| Thickness | Order yd³ | Order m³ | 80 lb bags | Rebar ft | Ready-mix | 80 lb cost |
|---|---|---|---|---|---|---|
| 4 in | 2.61 | 1.994 | 118 | 277 | $555.22 | $796.50 |
| 5 in | 2.85 | 2.180 | 129 | 277 | $595.56 | $870.75 |
| 6 in | 3.10 | 2.367 | 140 | 277 | $635.89 | $945.00 |
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 8 inches
Prepared by
Date
Verified by (PE / electrician / inspector)
License number
Signature
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 residential slab design features dimensions of 14 ft by 8 ft and a thickness of 8 inches, reinforced with #4 bars spaced at 18 inches. It is essential to ensure that the design complies with the International Residential Code (IRC) R506, which provides guidelines for concrete slabs.
Please note that soil design considerations are excluded from this calculation and should be assessed separately by a qualified professional.
Code reference
IRC R506
Field questions
- What is the purpose of using #4 bars in the slab?
- The #4 bars provide tensile strength to the concrete slab, helping to resist cracking and improve overall durability.
- Why is soil design excluded from this calculation?
- Soil design is site-specific and requires a geotechnical assessment to ensure proper load-bearing capacity, which is not included in this general slab calculation.
- What does IRC R506 cover?
- IRC R506 covers the requirements for concrete slabs, including thickness, reinforcement, and construction practices to ensure structural integrity.