Sidewalk Concrete Calculator: Yards, Bags and Cost

How to calculate concrete for a sidewalk

Select the closest path geometry and enter finished dimensions. Use a straight rectangle, a tapered section, a constant-width curve measured at its centerline, or an independently measured area. Multiply only genuinely identical sections.

Formulas

Straight area = length × width. Tapered area = length × (start width + end width) ÷ 2. Curved area = centerline arc length × width, where arc length = radius × angle in radians. Concrete volume = area × thickness. The allowance applies once before bags or ready-mix are calculated.

Checked example

A 50 × 4 ft sidewalk at 4 in thick has 200 ft² of area and 66.6667 ft³ of concrete. With 10% extra, order 73.3333 ft³ = 2.716 yd³. At 0.60 ft³ per bag, purchase 123 bags. A 5 ft panel limit creates nine interior cross-joint lines along the 50 ft run.

Important limits

• This tool estimates quantities from dimensions supplied; it does not select slab thickness, concrete strength, reinforcement, base design, drainage, slope or accessibility details.
• Joint spacing is a planning count only. Joint type, depth, timing, isolation and layout require project specifications and local practice.
• Curved paths must have a centerline radius greater than half the width so the inside edge remains physically meaningful.
• Edge-form length is geometric perimeter. It excludes stakes, overlaps, reusable boards, steps, intersections and existing edges that need no form.
• Bag yield, aggregate density, ready-mix minimums, delivery, short-load charges, tax and truck access must be confirmed with suppliers.

Related calculators

Use the Concrete Calculator for a basic slab, the Rebar Calculator for grid quantities, or the Square Footage Calculator for irregular measured areas.