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The total length of the sidewalk run.
Measure the full continuous length of the sidewalk run to be poured.
The maximum unbroken panel length allowed between control joints.
This commonly matches the sidewalk width, per ACI guidance, to control shrinkage cracking.
Control joints needed
19 control joints
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Concrete Sidewalk Control Joint Spacing Calculator: 19 control joints — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Control joints needed = ceil(sidewalk length ÷ maximum panel length) − 1, keeping each concrete panel within the standard maximum unbroken length to control shrinkage cracking (commonly matching the sidewalk width, per ACI guidance)
Inputs used
- Sidewalk Length
- 98 ft
- Maximum Panel Length (Commonly Matching Sidewalk Width)
- 5 ft
What this calculation does not cover
- Counts joints and says nothing about how they are made, which is what decides whether they work. A control joint has to be cut or tooled to at least a quarter of the slab depth — 25 mm (1 in) in a 100 mm (4 in) walk — and it has to be there early, tooled while the concrete is plastic or saw-cut within hours of set, before shrinkage stress finds its own path. A perfectly spaced joint that is too shallow or cut too late does not crack the slab on your line; the slab cracks where it wants and the joint sits empty.
- The sidewalk's WIDTH never enters this sum. Panels want to stay near square — beyond about one and a half times the width they crack across the middle whatever the joint count says — so a maximum panel length typed in without checking it against the actual width produces long thin panels that crack anyway. On a 1.5 m (5 ft) walk the real ceiling is around 2.2 m (7 ft), not whatever this box will accept.
- Control joints are not the only joints in a sidewalk. Full-depth isolation joints with a compressible filler go where the walk meets a building, a step, a driveway, a hydrant or a light pole, so the slab can move without dragging on them — a different detail, a different material and a quantity this count does not produce. Tool a control joint where an isolation joint belonged and the walk cracks off the fixed object instead.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Control joints needed = ceil(sidewalk length ÷ maximum panel length) − 1, keeping each concrete panel within the standard maximum unbroken length to control shrinkage cracking (commonly matching the sidewalk width, per ACI guidance)
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