SettingsSettings for this calculationUS
The total length of the expansion joint.
Sum all joint segments if there are multiple.
The width (gap) of the joint.
Typically 1/2 to 1 in (13-25mm) for slab expansion joints.
The depth of sealant or filler material within the joint.
Often less than the full slab depth if a backer rod is used to control sealant depth.
Filler volume needed
1.929 gal
They open the calculator with your figures already in it
Concrete Expansion Joint Filler Calculator: 1.93 gal — 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)
- Joint filler volume = joint length x joint width x joint depth, the standard geometric formula for a continuous sealed joint
Inputs used
- Joint Length
- 66 ft
- Joint Width
- 0.75 in
- Joint Depth (Sealant Fill Depth)
- 0.75 in
What this calculation does not cover
- No waste allowance. This is the bare geometric volume of the joint - it adds nothing for spillage, tooling loss, part-used cartridges, or offcuts when preformed filler board is cut to length and depth. Order in whole cartridges or boards above this figure.
- It assumes a solid rectangular fill across the full width and depth entered. A sealant bead tooled concave over a backer rod holds less than that, and the backer rod itself is neither counted nor sized here.
- This does not size the joint. Whether the width can absorb the movement expected at that location, and whether the fill depth suits the sealant's movement class, come from the specification and the sealant data sheet - the calculator only multiplies the three dimensions you give it.
- One constant cross-section is assumed over the whole run. There is no allowance for a joint that has opened or closed with the season since it was measured, saw-cut wander, a thickened slab edge, intersections and corners, or blockouts around columns and posts.
- Where the joint crosses a fire-rated floor or wall, the fill is a tested and listed fire-rated joint system with its own materials and fill depth, not a volume of ordinary sealant. Nothing here sizes or substitutes for that listing.
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 2026-09-03 · in the site-wide review of 2026-09-06 · v1.1.0
Regulatory standards & verification citations1
- Joint filler volume = joint length x joint width x joint depth, the standard geometric formula for a continuous sealed joint
Cite this page
Your workspace
Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.
Tools and safety for this job
To fit the isolation (expansion) joints against the house. Generic types, no brands, no prices.
Protection this work requires
- Boards, blocks and bagged material cause most lasting back injuries on small sites: two people or a lifter for full sheets, and never a bag on one shoulder up a ladder.
- Knives cause more site injuries than any power tool: cut away from your body, change blades often, and wear cut-resistant gloves to EN 388 level C for repeated cutting.
Show the 4 tools this job needsHide tools
Essential
Caulking gun
Tape measure
Utility knife
Recommended
Claw hammer
Also needed as materials: caulk and sealant cartridges, replacement blades.
what each concrete tool is for, and the spec that decides which to buy where one does.