How thick should a concrete sidewalk be?

Four inches is the common thickness for pedestrian sidewalks. Sections crossed by cars or service vehicles are commonly thickened to 6 inches or designed to local standards.

How much concrete does a 3-foot by 30-foot sidewalk need?

At 4 inches thick, the sidewalk contains 30 ft³, or 1.11 yd³ net. With 10% waste, order about 1.22 yd³.

How far apart should sidewalk joints be?

A common rule is to space control joints at roughly the slab width, creating near-square panels. Joint layout and depth should follow the project specification and local practice.

Sidewalk Concrete Calculator

Calculate concrete for a sidewalk or walkway from total length, width, and thickness. Estimate cubic yards, bags, weight, waste, and ready-mix material cost.

Sidewalk Dimensions

Results update as you change the formed dimensions.

Length

Width

Slab thickness

Waste allowance

Ready-mix price

$/yd³

Order quantity

1.22yd³ with waste

Slab area

90ft²

Net volume

30ft³

Concrete weight

4,950lb · 2.5 tons

60 lb bags

74bags

80 lb bags

55bags

Estimated ready-mix material cost

$256

Includes $60 short-load fee when the order is under 3 yd³. Labor, base, forms, reinforcement, finishing, tax, and other delivery charges are excluded.

Sidewalk Concrete Thickness and Volume

Four inches is typical for pedestrian sidewalks. Driveway crossings and areas exposed to vehicles commonly require 6 inches or a locally specified thickened section.

For multiple sidewalk runs, add their lengths when the width and thickness match. Calculate wider landings and driveway crossings as separate sections.

How to Calculate Concrete for a Sidewalk

Multiply the formed length by width and slab thickness after converting thickness from inches to feet. Divide cubic feet by 27 for cubic yards, then add the selected waste allowance.

Rectangular slab order

yd³ = length (ft) × width (ft) × [thickness (in) ÷ 12] ÷ 27 × (1 + waste%)

Measure the inside of the forms. Calculate thickened edges, footings, ramps, and separate pads independently.

Sidewalk Planning Checklist

Measure each run along its centerline and separate sections with different widths or thicknesses.
Provide cross-slope and drainage consistent with accessibility and local requirements.
Use isolation joints at buildings and existing slabs, plus regularly spaced control joints.
Treat driveway crossings as heavier-duty slab sections.