What is the thickness of the slab?

The slab is designed to be 5 inches thick.

What type of reinforcement is used?

The slab is reinforced with #4 bars spaced at 18 inches.

What are the dimensions of the slab?

The dimensions of the slab are 14 ft by 24 ft.

Which code should I refer to for slab design?

Refer to IRC R506 for compliance in slab design.

14 by 24 ft slab at 5 inches

Calculate the specifications for a 14 ft by 24 ft residential slab at 5 inches thick with #4 bars at 18 inches. Ensure compliance with IRC R506 standards.

Formula SSC-2026.1

Formula SSC-2026.1 · 4,000 PSI

Order volume

5.70 yd³

4.361 m³ placed+waste

Order weight

23,100 lb

10,478 kg

80 lb bags

257

7 pallets at 42 bags

60 lb bags

343

0.45 ft³ yield each

Rebar

478.00 ft

37 × 20 ft · 37 × 6 m · 351 lb

Ready-mix vs bags

$941.11

Truck $941.11 · 80 lb bags $1,734.75

Slab footprint and rebar gridLive scaled blueprint

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.

Bill of materials and shopping list
Item	Net	Waste	Order	Unit price	Line total	Source Spec Material / Tool
Ready-mix concrete	5.19 yd³	10%	5.70 yd³ / 4.361 m³	USD	$941.11	Source Spec Material / Tool
Short-load fee	Full load	—	1 truck @ 10 yd³	USD	$0.00	Source Spec Material / Tool
80 lb pre-mix bags	233.3 bags	10%	257 bags	USD	$1,734.75	Source Spec Material / Tool
60 lb pre-mix bags	311.1 bags	10%	343 bags	USD	$1,852.20	Source Spec Material / Tool
#4 rebar sticks, 20 ft	37 sticks	10%	41 sticks / 37 × 6 m	USD	$574.00	Source Spec Material / Tool
Rebar chairs	170 crossings	10%	187 chairs	USD	$52.36	Source Spec Material / Tool
Tie wire rolls	170 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

$941.11

0.57 nominal 10 yd³ loads · 1 to order

80 lb bags

$1,734.75

60 lb alternative $1,852.20 · delivery weight 23,100 lb

Side-by-side thickness comparison at the same footprint
Thickness	Order yd³	Order m³	80 lb bags	Rebar ft	Ready-mix	80 lb cost
4 in	4.56	3.489	206	526	$752.89	$1,390.50
5 in	5.70	4.361	257	526	$941.11	$1,734.75
6 in	6.84	5.233	308	526	$1,129.33	$2,079.00

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 24 ft slab at 5 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 calculator helps you determine the requirements for a residential slab measuring 14 ft by 24 ft and 5 inches in thickness, reinforced with #4 bars spaced at 18 inches. Please note that soil design considerations are excluded from this calculation.

For compliance with the International Residential Code (IRC) R506, ensure that all local building codes and regulations are followed when designing and constructing your slab.

Code reference

IRC R506

Field questions

What is the thickness of the slab?: The slab is designed to be 5 inches thick.
What type of reinforcement is used?: The slab is reinforced with #4 bars spaced at 18 inches.
Is soil design included in this calculation?: No, soil design considerations are excluded from this calculation.
What are the dimensions of the slab?: The dimensions of the slab are 14 ft by 24 ft.
Which code should I refer to for slab design?: Refer to IRC R506 for compliance in slab design.