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SlabCosts
Step-by-step · 2026

Patio: Concrete Calculator Guide

Plan your patio in build order — base, rebar, concrete and cost, each sized for your dimensions.

A concrete patio is one of the most satisfying DIY pours. Work through the steps below in order — set your patio size once and each calculator picks it up — to plan the gravel base, reinforcement, concrete and cost without re-typing a single measurement.

Your patio size

Width (ft)
Length (ft)
Thick (in)

This patio needs

1.96 yd³

≈ $792 – $1,728 installed

  1. 1

    Measure & mark the area

    Set your width and length above. Square off the corners and mark the perimeter. Not a simple rectangle? Work out the area with the square footage calculator first.

    Square footage calculator
  2. 2

    Excavate & lay the gravel base

    Dig down for the slab plus about 4" of base, then lay and compact crushed gravel so the slab drains and won't heave. This is the volume of base to order.

    Gravel base calculator
  3. 3

    Set forms & add rebar

    Build your forms to the finished height, then lay a two-way rebar or wire-mesh grid on chairs to control cracking. Here's the rebar to buy.

    Rebar calculator
  4. 4

    Pour, screed & finish the concrete

    Order or mix the concrete, pour into the forms, screed level, then float and finish. This is the concrete volume and bag count, with 10% waste built in.

    Concrete slab calculator
  5. 5

    Budget the total cost

    See what the finished slab costs — materials if you DIY, or fully installed by a contractor — for your exact size.

    Patio slab cost

Typical patio sizes & cost

SizeConcrete (4")Installed cost
10×10 1.36 yd³ $550 – $1,200
12×12 1.96 yd³ $792 – $1,728
12×16 2.61 yd³ $1,056 – $2,304
16×20 4.35 yd³ $1,760 – $3,840
Prices updated January 2026 National US averages · reviewed quarterly

Volumes use standard bag yields and a 10% waste allowance; costs are national US averages that vary by region, mix and finish. See our methodology for exactly how each figure is worked out, or check the reference sources:

Other project guides

Driveway guide Plan your driveway in build order Garage guide Plan your garage floor in build order Shed guide Plan your shed pad in build order Fence post guide Post holes & footings

Frequently asked questions

How thick should a concrete patio be?
4" is standard for a patio carrying foot traffic and furniture.
Do I need rebar in a patio?
A light rebar or wire-mesh grid is recommended to control cracking, though small patios are sometimes poured with fiber mesh instead.
What order do I build a patio in?
Measure and excavate, lay and compact the gravel base, set forms and rebar, pour and finish the concrete, then cure. The steps above follow that order.