UNDERSTAND YOUR ESTIMATE
How this calculator works
Multiply slab length by width to get square footage, then multiply that area by the published installed rate for the selected thickness. Demolition, grading, reinforcement, finish and access are intentionally left out of the form until compatible non-overlapping adjustments are verified.
Major factors affecting the result
- Slab area and selected thickness determine the modeled installed range.
- Base preparation, reinforcement and access can materially change a contractor quote.
- Decorative finishes and removal of existing concrete need separate, non-overlapping prices.
Typical project ranges
2-inch slab
$4–$6 per sq ft installedA pricing band, not a recommendation for structural use.
4-inch slab
$6–$8 per sq ft installedCommon source category for residential slab pricing.
6-inch slab
$8–$10 per sq ft installedThicker slab pricing before project-specific extras.
8-inch slab
$10–$12 per sq ft installedStructural design and reinforcement remain outside the model.
Put the numbers in context
A 20 × 20 ft slab has 400 sq ft. At the published 4-inch installed rate of $6–$8 per sq ft, the planning range is $2,400–$3,200 and the midpoint is $2,800.
What is not included
Demolition, disposal, grading, gravel base, reinforcement, pumping, permits, drainage corrections and decorative finishes are not added separately. The selected thickness is a pricing input, not an engineering recommendation.
When to get a professional quote
Use the result to organize your questions and compare the same scope across written quotes. Confirm inclusions, exclusions and site conditions with the person doing the work. For structural, electrical, HVAC or tree-hazard decisions, consult a qualified professional.
Frequently asked questions
Does this tell me how thick the slab should be?
No. Choose a thickness only after confirming the intended load, soil, reinforcement and local requirements with a qualified professional.
Are grading and old-concrete removal included?
No. They are excluded from the estimate and are not shown as calculator inputs until a verified non-overlapping adjustment is available.
Can I use this for irregular shapes?
Break the plan into rectangles, calculate each area separately and add the ranges. Curves and complex formwork may increase the quote.
Data sources & methodology
Last reviewed: September 2026.
Low and high use the linked published ranges. Typical is the arithmetic midpoint only when both bounds are closed. If a source prints an upper value with “+”, Typical is not calculated. No regional, material-quality or difficulty multiplier is applied. Source ranges may describe different scopes and should not be treated as guarantees.
2-inch slab
$4–$6 per sq ft installed · HomeGuide cost guide
Installed slab range by thickness. The calculator does not determine whether 2 inches is suitable for the intended load.
Published February 3, 2026 · Accessed September 17, 2026 · Typical: derived midpoint4-inch slab
$6–$8 per sq ft installed · HomeGuide cost guide
Installed slab range by thickness. Four inches is a source pricing category, not a design recommendation.
Published February 3, 2026 · Accessed September 17, 2026 · Typical: derived midpoint6-inch slab
$8–$10 per sq ft installed · HomeGuide cost guide
Installed slab range by thickness. Reinforcement, base preparation and site conditions still require a project quote.
Published February 3, 2026 · Accessed September 17, 2026 · Typical: derived midpoint8-inch slab
$10–$12 per sq ft installed · HomeGuide cost guide
Installed slab range by thickness. Structural requirements must be confirmed for the intended use.
Published February 3, 2026 · Accessed September 17, 2026 · Typical: derived midpointItemized charges without a verified, non-overlapping basis remain unpriced. “Quote needed” does not mean free. An installed baseline is never silently split into invented cost percentages.