Calculator Home /Standard Footprints/30x40 Slab & Building Specs
40' LENGTH (2 BAYS) 30' WIDTH 1,200 SQ FT | 4" SLAB | ~22 YD3
Concrete Volume ~22 YD³
9-Yd Mixer Trucks 3 Trucks
Total Wet Weight 44.55 Tons
30x40 FOOTPRINT | 1,200 SQ FT | 3-BAY WORKSHOP & GARAGE SPEC

30' x 40' Concrete Slab & Metal Building Specifications (1,200 Sq Ft)

Engineering volume, weight, bag equivalents, and rebar requirements for a 30' x 40' (1,200 sq ft) monolithic concrete foundation and metal building footprint.

Footprint Area & Perimeter 1,200 sq ft (140 LF Perimeter)
Slab Thickness & Grade Beam 4" Deck | 12" x 18" Perimeter Grade Beam (140 LF) + Center Cross Beam
Ready-Mix Volume (+10% Waste) ~22 YD³ (594 FT³)
Pre-Mixed Bag Equivalent 990 x 80-lb (1,320 x 60-lb)
Deformed Rebar Footage ~1,620 LF (#3 Rebar @ 18" OC (or #4 @ 12" OC Heavy Shop Upgrade))
DFW DOT Bid Foundation Index $8,690 - $18,300 (Slab Benchmark)
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Engineering Specifications (30x40)

  • 1,200 sq ft total footprint (30 ft width x 40 ft length)
  • ~22 cubic yards (594 cu ft) of ready-mix concrete including 140 LF perimeter grade beam, interior cross beam, and waste allowance
  • 89,100 lbs (44.55 short tons) total wet weight at 150 lbs/cu ft (equivalent to 990 x 80-lb bags)
  • 3 standard 9-yard ready-mix concrete mixer truck loads
  • ~1,620 linear feet of deformed Grade 60 rebar + 1,350 sq ft of 10-mil polyethylene vapor barrier
  • 6 structural column anchor locations (24 anchor bolts) across two 20-ft bays

Common Applications & FAQs

  • Three-bay residential workshop and pickup truck garage
  • Acreage equipment storage for compact tractors, trailers, and tools
  • Monolithic foundation for a 30x40x12 pre-engineered bolt-up or weld-up steel building
How many cubic yards of concrete do I need for a 30x40 slab?
A flat 4-inch slab measuring 30x40 (1,200 sq ft) requires 14.8 cubic yards for the flat floor alone. Including a 140 LF thickened 12" x 18" perimeter grade beam, one interior cross beam, and an 8% waste allowance brings the total to approximately 22 cubic yards (25 to 26 cubic yards if poured at 5 inches thick).
Should I pour a 4-inch or 5-inch slab for a 30x40 shop?
A 4-inch slab (3,000 PSI) is standard for pickup trucks, SUVs, and general workshop use. If you plan to install a 2-post automotive lift or park heavy equipment, upgrading to a 5-inch slab (3,500 PSI with #4 rebar on 12-inch centers) provides higher point-load capacity.

Other Standard Building & Slab Sizes

24' x 30' (720 sq ft) ~12 YD³ | 2 Trucks | $5,210 - $10,980 30' x 50' (1,500 sq ft) ~31 YD³ | 4 Trucks | $10,860 - $22,875 40' x 60' (2,400 sq ft) ~49 YD³ | 6 Trucks | $17,375 - $36,600 50' x 80' (4,000 sq ft) ~85 YD³ | 10 Trucks | $28,960 - $61,000 60' x 100' (6,000 sq ft) ~135 YD³ | 15 Trucks | $43,440 - $91,500

CONCRETE & BUILDING CALCULATOR

Calculate exact ready-mix cubic yards, 9-yard mixer truck loads, bag counts, weight, and TxDOT foundation cost benchmarks instantly.

DIMENSIONS & SLAB SPEC
FT
FT
FT
PROJECT SCOPE
  • → Includes thickened 12"x24" perimeter grade beams and 8% subgrade waste factor
  • → 3,500 PSI ready-mix within a 90-minute ASTM C94 batch-plant radius
  • → Anchor-bolt layout matched to Mueller, Prime, Brazos, or custom weld-up frames
TECHNICAL RESULT LIVE SPEC
~31 Cu. Yds.
Includes 12"x24" perimeter beam & 8% waste factor • 1,500 SF (14'H)
9-YD MIXER TRUCKS 4 Trucks (62.8T) Batch-plant delivery
BAGS (80LB EQUIV) 1,395 Bags At 150 lbs / cu ft
GRADE BEAM & REBAR 160 LF / 3,640 LF Beam / Deformed Bar
READY-MIX MATERIAL ~$5,208 ~31 Cu. Yds. @ $168/yd
TXDOT / DFW FOUNDATION BENCHMARK 1,500 sq ft @ $7.24 - $15.25/sf Selected Scope: Slab + 6"-18" Select Fill Pad.
$10,860 - $22,875 Median $11.25/sq ft (~$16,875)
LOCK IN THIS SPEC & REQUEST LOCAL QUOTE ↓
View 2D Anchor-Bolt Plan, 3D Slab Cutaway & Kit Options
30' W x 50' L x 14' H (1,500 SQ FT)
ANCHOR BOLT & BEAM PLAN 30' x 50' (8 Anchor Columns) 160 LF Grade Beam + 5' Pad Apron 5" REINFORCED SLAB (3,500 PSI) | 1,500 SQ FT #4 Rebar @ 12" OC | 12" x 24" Grade Beam (160 LF) 6"-18" SELECT FILL PAD + 10-MIL VAPOR BARRIER READY-MIX: ~31 CU. YDS. (4 TRUCKS | 62.8 TONS)
26-GA COLOR: Limestone Tan / Burnished Slate
GET YOUR LOCAL SITE QUOTE & SPEC SHEET Submit your property details below to route this volume takeoff to our local North Texas concrete & building crew.
Selected: 30' x 50' (1,500 SF) | ~31 Cu. Yds.
PREFERRED DELIVERY CHANNELS:

How It Works

From instant concrete yardage takeoff to on-site laser elevation verification in 4 steps.

STEP 01

Calculate Your Slab & Building

Select a standard 24x30 to 60x100 footprint or enter custom dimensions to get exact cubic yards, mixer trucks, and DOT cost benchmarks.

STEP 02

Choose Your Trade Scope

Select Concrete Slab Only, Slab + Select-Fill Pad, Pre-Engineered Kit Erection, or a complete Dirt-to-Finish Turnkey Building.

STEP 03

Batch-Plant & Pad Check

We verify your ZIP code's 90-minute ready-mix haul radius, soil plasticity index, and laser pad slope for an accurate local quote.

STEP 04

Direct Local Crew Dispatch

Your spec sheet routes one-to-one to our designated county concrete and steel erection crew with zero broker spam.

Concrete Foundation & Kit Erection Guides

Field guides covering monolithic grade beams, low-PI select fill pads,
Mueller/Prime/Brazos kit erection, and Texas Chapter 233 county rules.

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What does an engineered monolithic concrete foundation actually cost across Weatherford, Granbury, Stephenville, and Decatur in 2026? Here is the exact line-item breakdown for 3,000 to 4,000 PSI ready-mix, #3 vs #4 deformed rebar grids, 12x24 perimeter grade beams, and compacted select fill pads.

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Mueller Inc., Prime Metal Buildings, Brazos Metal Building Systems, and JAG Metals manufacture outstanding steel building packages across North Texas, but none of them pour concrete slabs or erect the steel. Here is how much erection labor, anchor-bolt coordination, and foundation work cost in 2026.

READ GUIDE → Price My Mueller / Prime Kit Erection + Slab
Permits, Codes & Acreage Rules 7 min read

Do You Need a Building Permit for a Metal Shop or Barndominium on Unincorporated Land in Parker, Hood, Wise or Erath County? (Texas Chapter 233)

Over 80% of our concrete slab and metal building builds happen on unincorporated 1-to-50 acre tracts outside municipal city limits. Here is what Texas Local Government Code Chapter 233 allows, which county permits STILL apply (septic, floodplain, driveway culverts), and how incorporated city permits work.

READ GUIDE → Price a 40x60 Unincorporated Acreage Shop + Slab