Caulk Calculator
Enter the total joint length, width, and depth to get how many 10 oz tubes of caulk you need.
Joint
A standard 10 oz caulk tube covers ~17 cu in. Use a backer rod to reduce depth on gaps over 1/2".
You'll need
Add 10–15% for waste and imperfect beads. Use backer rod for joints deeper than 1/2" to save caulk and prevent three-point adhesion.
How to estimate caulk
Caulk volume is joint width × joint depth × length. A 10 oz tube holds about 17 cubic inches. Wider or deeper joints use dramatically more — doubling both dimensions quadruples the caulk needed. Use backer rod for deep gaps.
Measure perimeters and joint runs from a scan
ProBuildCalc turns your iPhone's LiDAR scanner into a job-site measuring kit — walk the space and it captures the square footage, material takeoff, and a blueprint automatically. No tape measure, no graph paper.
Caulk calculator FAQ
- How many linear feet does a tube of caulk cover?
- A standard 10 oz tube covers about 30–50 linear feet at a 1/4-inch wide by 1/4-inch deep bead. Wider or deeper joints use proportionally more — a 1/2-inch joint at 1/2-inch deep uses roughly 8 times as much caulk.
- How do I calculate caulk needed?
- Multiply joint width by joint depth (in inches) to get the cross-section, then multiply by the joint length in feet and divide by the tube volume (~17 cubic inches for a 10 oz tube). The calculator above does this automatically.
- Should I use a backer rod?
- Yes, for any gap deeper than 1/2 inch. Backer rod fills the gap before caulking so you use less caulk, and it prevents three-point adhesion — which causes caulk to tear as materials expand and contract.
- What type of caulk should I use?
- Silicone for exterior joints, wet areas, and glass. Paintable latex (acrylic) for interior trim and drywall gaps. Polyurethane for wide exterior gaps and concrete. Always check that the product is rated for your application.
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See also: estimating guides · ProBuildCalc by trade