Concrete Slab Volume Calculator
Calculate concrete volume needed for a slab in cubic yards. Enter length, width, and thickness to get accurate material estimates for your project.
Precast Concrete Calculator
Calculate precast concrete piece volume and total weight. Enter dimensions and piece count for project planning, crane capacity, and transport.
ft
ft
in
Per Piece⧉
8.00 tons
106.7 ft³
Total Weight⧉
96.0 tons
192,000 lbs
Total Volume⧉
47.4 yd³
Truck Loads⧉
4
@ 48,000 lbs/truck
Planning notes, formulas, and examples
About the Precast Concrete Calculator
Precast concrete elements — panels, beams, planks, barriers, and architectural components — are manufactured in a controlled factory environment and transported to the job site for installation. Knowing the volume and weight of each piece is essential for crane selection, transport planning, and structural design.
This calculator computes the concrete volume per piece and total weight based on dimensions, piece count, and concrete density. Standard concrete weighs approximately 150 lbs/ft³ (normal weight) or 115 lbs/ft³ (lightweight). Hollow-core planks and other voided sections weigh less than solid sections.
Accurate weight calculations determine crane capacity requirements, truck load limits, and rigging configurations. Under-estimating weight can create dangerous lifting conditions, while over-estimating leads to unnecessarily expensive crane rentals.
When This Page Helps
Precast piece weight determines crane size, truck capacity, and rigging requirements. It gives per-piece volume and weight along with total project weight for transport and installation planning.
How to Use the Inputs
- Enter the length, width, and depth of each precast piece.
- Enter the total number of pieces.
- Select concrete type (normal weight or lightweight).
- Review per-piece volume and weight plus total project weight.
- Use the weight for crane capacity planning and shipping logistics.
Formula used
Volume per piece = Length (ft) × Width (ft) × Depth (in) ÷ 12
Weight per piece = Volume (ft³) × Density (lbs/ft³)
Total weight = Weight per piece × Number of pieces
Normal weight concrete: 150 lbs/ft³
Lightweight concrete: 115 lbs/ft³Example Calculation
Result: 96,000 lbs (48 tons) total
Each panel: 20 × 8 × 8/12 = 106.7 ft³. Weight: 106.7 × 150 = 16,000 lbs (8 tons) per piece. Total: 16,000 × 12 = 192,000 lbs = 96 tons for all 12 panels.
Tips & Best Practices
- Always verify piece weight with the precast manufacturer — reinforcement and inserts add 3–5% to bare concrete weight.
- Hollow-core planks weigh 50–70% of equivalent solid sections due to internal voids.
- Standard flatbed trucks carry 40,000–48,000 lbs per load; plan pieces per truck accordingly.
- Crane capacity must exceed the heaviest single piece by a safety factor — typically 75–85% of rated capacity.
- Consider pick points and rigging geometry — off-center lifts require derating the crane capacity.
- Include the weight of lifting hardware, spreader bars, and rigging in crane capacity calculations.
Common Precast Elements
Wall panels: architectural and structural, 6–12" thick. Double tees: floor/roof members with two stems, spans to 60'+. Hollow-core plank: floor/roof slabs, 4–16" deep, spans to 40'. Beams and girders: rectangular or inverted-T, various sizes. Columns: square or round, typically 12–36" cross-section.
Transport and Erection
Precast elements are transported by flatbed truck and erected by crane. Erection sequence is planned to minimize crane repositioning. Pieces are typically connected with grouted joints, welded connections, or bolted hardware.
Quality Advantages
Factory production provides controlled curing, tight tolerances (±1/8" typical), high-quality finishes, and consistent strength. Precast achieves 5,000–8,000 PSI compressive strength, exceeding most cast-in-place concrete.
Sources & Methodology
Last updated:
Frequently Asked Questions
Normal weight precast: 150 lbs/ft³. Lightweight precast: 110–120 lbs/ft³. These densities include reinforcing steel. Actual weight depends on the mix design and reinforcement quantity.
A solid precast wall panel 8" thick weighs about 100 lbs/ft². An insulated sandwich panel (2" concrete + 3" foam + 3" concrete) weighs about 60 lbs/ft². A 20' × 10' solid panel weighs approximately 10 tons.
Most precast panels (5–20 tons) require a 50–100 ton hydraulic crane. Longer reaches or heavier pieces may require 150+ ton cranes. The crane's capacity diminishes with boom length and radius — always check the load chart.
Legal truck weight limit is about 48,000 lbs of cargo. A typical flatbed carries 2–4 wall panels or 4–8 hollow-core planks per load. Oversize permits may be needed for pieces wider than 8' or longer than 60'.
Hollow-core planks are precast concrete slabs with internal cylindrical voids running their length. This reduces weight by 30–50% while maintaining structural capacity. They're commonly used for floors and roofs in commercial construction.
Add 3–5% to bare concrete weight for mild reinforcement. Prestressed elements (with tensioned strands) add 1–3%. For precise weights, the precast manufacturer provides certified piece weights based on their shop drawings.
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