Concrete

Concrete Slab Calculator

Estimate concrete volume, bags, material weight, mixer batches, and an optional bagged-versus-ready-mix cost check using only the prices and fees you enter.

Written by Arthur Weng Reviewed July 14, 2026 Sources

Concrete

Calculator inputs

Quick startChoose a common size, then adjust any field.

Project dimensions

Slab lengthftSlab widthftSlab thicknessin

Material specification

Use the yield shown on the concrete bag whenever possible.

Bag yield presetPreset yields are planning approximations. Use the product label when possible.

Purchase adjustments

Add overage and your own unit price only when needed.

Waste factor%Your bag price (optional)$/bag

Mixing plan

Use your mixer capacity and pace to estimate the number of batches and active mixing time.

Bags per mixer batch (optional)bagsEnter the capacity you actually use for one batch; check the mixer instructions.Minutes per batch (optional)minAdds a simple mixing-time estimate when bags per batch is also entered.

Custom bag settingsUse these fields only when they match the product label.

Custom bag yieldcu ft/bagUsed only when Custom yield below is selected. Copy the yield from the product label.Custom bag weight (optional)lb/bagUsed only with a custom bag yield to estimate the total packaged weight.

Ready-mix cost checkOptional: enter a supplier price, minimum order, and fees you already have. The calculator does not fetch or recommend prices.

Your ready-mix price (optional)$/cu ydEnter a supplier value you already have. This site does not look up prices.Ready-mix minimum order (optional)cu ydIf your supplier has a minimum, enter it so the cost uses the larger of the required volume or minimum order.Your ready-mix delivery fee (optional)$Your ready-mix short-load fee (optional)$

Enter your own local prices or fees only if you want a cost estimate.

Calculated in your browser.Project dimensions stay on this device. Review the assumptions below before buying material.

Concrete Slab Calculator Results

Results update in your browser as you edit inputs. Use the shopping-list button for a printable project summary.

Enter project dimensions to calculate material quantity.

Detailed guide

Need the assumptions, examples, and troubleshooting?

The calculator stays focused here. The supporting reference has moved to its own page.

Read the Concrete Slab Calculator guide