Concrete Slab & Footing Takeoff Calculator
Combine slabs, footings, grade beams, walls and rectangular columns to estimate concrete CY, order quantities, optional reinforcement and formwork. Enter the number of identical physical elements; the calculator generates concrete quantities.
Concrete Slab & Footing Takeoff Calculator
Add slabs, footings, walls, grade beams and rectangular piers to generate concrete, reinforcement and formwork quantities.
Need a Complete Concrete Takeoff?
Get drawing-based quantities for slabs, foundations, walls, reinforcing steel, formwork and related concrete scope.
Concrete Estimating ServicesHow to Use the Concrete Calculator
- Select the concrete element type and give the item a useful name.
- Enter actual concrete dimensions in the units shown.
- Enter the number of identical physical elements.
- Add additional concrete items for other dimensions or element types.
- Select optional reinforcement and formwork assumptions.
- Set project-level concrete overage.
- Select Exact calculated CY or an order increment.
- Calculate the combined takeoff and review each item.
Dimensions describe the concrete itself, not excavation. “Number of footings” means how many matching footings are being built; it is not a cubic-yard input. The calculator generates concrete quantities from the geometry and physical count.
Concrete Volume and Cubic Yards
27 cubic feet equals 1 cubic yard. This concrete volume calculator converts inch dimensions to feet, multiplies the three dimensions and physical count, then divides cubic feet by 27. Keep the units shown beside each field; entering an inch value into a foot field changes the result substantially.
Slabs
The concrete slab calculator uses length (ft) × width (ft) × thickness (in. ÷ 12) × number of slabs. It also reports slab area in square feet.
Strip Footings and Grade Beams
Use length in feet, with width and depth in inches. Volume is length × (width ÷ 12) × (depth ÷ 12) × number of identical runs. Give differently sized runs separate items.
Pad Footings
The concrete footing calculator uses length and width in feet and depth in inches. Multiply the resulting volume by the number of matching pads. Four 5 × 5-ft pads, each 18 inches deep, contain approximately 5.5556 CY.
Concrete Walls
Wall volume is length (ft) × height (ft) × thickness (in. ÷ 12) × number of walls. Wall face SF is length × height × count; it is separate from concrete volume.
Rectangular Columns and Piers
Enter section width and depth in inches, height in feet and the number of columns. V1 supports rectangular sections only, including square sections. It does not calculate circular piers or sonotubes.
Custom Rectangular Volume
Use length × width × depth, all in feet, multiplied by the number of identical items. This is a simple rectangular-volume option when a predefined type is not appropriate; it does not model irregular geometry.
Combine Multiple Concrete Items in One Takeoff
Build one project takeoff from slabs, strip footings, pads, grade beams, walls and rectangular columns. Use one item with a physical count for identical elements, and separate items when dimensions differ. Names such as “Garage slab,” “F1 pads” and “North wall” make the result easier to review.
The concrete takeoff calculator reports each item's net CY and a combined project total. Review the breakdown before ordering so no element is omitted or counted twice. Changing inputs clears the prior result until you calculate again.
Concrete Overage and Ready-Mix Order Rounding
Net concrete → project overage → order rounding. The default overage is 5%, editable from 0% to 25%. It is applied once to the combined net concrete, not repeatedly to individual subtotals. Five percent is an estimating starting point, not a mandatory allowance for every project.
Select Exact calculated CY, 0.25 CY, 0.5 CY or 1.0 CY. Exact mode retains the calculated order quantity before increment rounding; displayed decimals are rounded for readability. The other options round upward, never to the nearest increment. For example, 15.56 CY at a 0.5-CY increment becomes 16 CY.
Confirm the appropriate allowance, delivery quantities and ordering requirements with the project team and ready-mix supplier. The supported combined net-concrete limit is 100,000,000 CY.
Slab Rebar Grid and Rebar Weight
This slab rebar calculator estimates a user-specified layout using #3 through #8 bars. Bars are estimated at both slab edges. Spacing determines the bar count across the dimension perpendicular to the bar run, with an additional edge bar where needed.
In one-direction mode, bars run along the slab Length. Both-direction mode adds bars running along the Width. Calculated bar lengths multiply by the number of slabs, then the optional lap/waste percentage is applied to LF.
The concrete rebar calculator converts those LF into approximate weight using standard nominal weights for #3–#8. It does not choose a required bar size, spacing, cover or structural reinforcing design.
Reinforcement Quantity Example
A 40 × 30-ft slab with #4 bars at 18 inches O.C., both directions and 0% allowance produces 1,680 LF and approximately 1,122 lb. One direction produces 840 LF. These figures demonstrate the tool's quantity convention; they are not a recommended structural layout.
WWR / Wire Mesh
Enter the actual coverage per sheet or roll from the selected product. Required units equal slab SF × (1 + mesh waste percentage ÷ 100) ÷ coverage, rounded upward to whole sheets/rolls. Mesh waste is separate from concrete overage.
For example, 100 SF with 10% mesh waste and 110-SF coverage requires one sheet/roll. Use coverage appropriate to the product and planned layout, and review laps and cutting requirements.
Footing and Grade-Beam Longitudinal Bars
Optional longitudinal reinforcement uses element length × number of longitudinal bars × number of identical runs × the lap/waste factor. The result is reported in LF and approximate weight for the selected bar size. V1 estimates these entered bars; it does not design stirrups or ties.
Formwork Quantities
The concrete formwork calculator reports the selected supported surfaces:
- Slabs: perimeter LF = 2 × (length + width) × slab count.
- Strip footings and grade beams: two-side contact SF = length × depth in feet × 2 × run count.
- Walls: one-side face SF or twice that area for two sides.
- Pad footings: four-side contact SF = pad perimeter × depth in feet × pad count.
- Rectangular columns/piers: section perimeter in feet × height × column count.
Select None when a form quantity is not required. These are perimeter or form-contact measurements, not forming-system design or plywood purchase schedules.
Worked Concrete Takeoff Examples
40 × 30-ft Slab, 4 Inches Thick
One slab contains 40 × 30 × (4 ÷ 12) = 400 cubic feet. With 5% project overage and a 0.5-CY increment, the verified live results are:
| Quantity | Result |
|---|---|
| Slab area | 1,200 SF |
| Net concrete | 14.8148 CY |
| With 5% overage | 15.5556 CY |
| Rounded order | 16 CY |
| Slab edge forms | 140 LF |
Slab, Strip Footing and Four Pads
Combine that slab with one 100-ft strip footing, 24 inches wide × 12 inches deep, and four 5 × 5-ft pads, each 18 inches deep. The concrete yard calculator reports 27.7778 CY net → 29.1667 CY with 5% overage → 29.5 CY ordered at the 0.5-CY increment.
What This V1 Tool Does Not Cover
V1 does not model circular piers, sonotubes, stairs, curbs/gutters, irregular or sloped slabs, turndowns or haunches. It does not calculate excavation, soil swell/shrink, mix proportions, pricing, pump sizing or labor productivity. Structural concrete sizing, reinforcement design and stirrup/tie design remain outside its scope.
Frequently Asked Questions
How do I calculate concrete cubic yards?
Convert dimensions to feet, multiply length × width × depth and the physical element count, then divide cubic feet by 27. The tool handles the conversions for each labeled element type.
How many cubic feet are in a cubic yard?
There are 27 cubic feet in one cubic yard. A 3 × 3 × 3-ft volume is one CY.
How much concrete do I need for a slab?
Enter slab length and width in feet, thickness in inches and the number of matching slabs. Review net CY, then add your selected overage and order increment.
How do I calculate concrete for footings?
Select Strip Footing for continuous runs or Pad Footing for individual rectangular pads. Follow the units shown and enter the physical run or footing count.
Can I calculate several slabs and footings together?
Yes. Add an item for each different size or type. The result shows individual net quantities and one combined concrete total.
How much extra concrete should I order?
V1 defaults to 5%, but the suitable allowance depends on the project and placement conditions. Adjust it with the project team and supplier; the calculator applies it once before order rounding.
Can this calculator estimate rebar?
Yes, for user-specified slab grids and longitudinal strip-footing or grade-beam bars. It reports LF and approximate weight without determining structural requirements.
How does the slab rebar grid calculation work?
It estimates bars at both edges and uses spacing across the perpendicular dimension. One-direction bars run along Length; both directions add Width-running bars. The selected lap/waste allowance increases total LF.
Can it calculate wire mesh?
Yes. Select WWR / Wire Mesh, enter coverage per sheet/roll and mesh waste, and the calculator rounds the required units upward.
Does the calculator estimate formwork?
Yes. It reports slab perimeter LF and selected side-contact SF for supported footings, beams, walls and rectangular columns. It does not produce a forming-system or plywood schedule.