Concrete Sidewalk Calculator

A walk is long and narrow

Sidewalks and garden paths use little concrete per foot but run a long way, so small errors in width or thickness add up. A 50 ft walk 4 ft wide at 4 in needs 2.72 cu yd with waste, or 123 bags of 80 lb.

Measure along the center line on curved paths. For a walk that turns a corner, run each straight leg on its own and add them.

Control joints keep cracks in line

Concrete shrinks as it cures and tends to crack. Control joints are grooves cut or tooled across the walk so cracks form there instead of at random. A common habit is to space them about as far apart in feet as the walk is wide, so a 4 ft walk gets joints every 4 to 5 ft.

The calculator counts the joints between the ends. In the example, joints every 5 ft along 50 ft give 9 joints.

Forms on both sides

A walk needs form boards along each long edge, so the form length is twice the walk length: 100 lin ft for the 50 ft example. Add stakes every few feet and extra boards or flexible forms for curves.

Lumber for forms is covered by the lumber calculator if you want a full board count.

Slope and base

Set the forms so the walk sheds water to one side, away from the house. A gentle cross slope is enough. Lay and compact a gravel base first, then check the thickness at several spots before the pour.

Where a walk meets the public sidewalk or street, local rules may set the width, thickness and slope. The local building code and your town have the final word there.

Next steps

If the walk ends at a stoop, the concrete step calculator handles the stairs. For a wider area like a patio, the concrete slab calculator is a better fit.