How this calculator works
A bead of caulk is a long thin box. Its volume is the joint's length × width × depth, and a cartridge holds a fixed volume: 10.1 fluid ounces is about 18.2 cubic inches. Divide the joint volume (plus a margin) by the cartridge volume and round up.
Worked example: 40 ft of a 1/4 × 1/4 in joint is 480 in × 0.0625 in² = 30 in³. With 10% extra that is 33 in³, or 18.3 fl oz, which is two standard 10.1 oz tubes. One tube covers about 24 ft of a 1/4 × 1/4 in joint.
Feet of joint per standard (10.1 oz) tube
| Joint depth | 1/8 in wide | 3/16 in wide | 1/4 in wide | 3/8 in wide | 1/2 in wide |
|---|---|---|---|---|---|
| 1/8 in | 97.2 ft | 64.8 ft | 48.6 ft | 32.4 ft | 24.3 ft |
| 3/16 in | 64.8 ft | 43.2 ft | 32.4 ft | 21.6 ft | 16.2 ft |
| 1/4 in | 48.6 ft | 32.4 ft | 24.3 ft | 16.2 ft | 12.2 ft |
| 3/8 in | 32.4 ft | 21.6 ft | 16.2 ft | 10.8 ft | 8.1 ft |
Tips before you buy
- Match the caulk to the job: silicone for kitchens, baths and glass; acrylic latex (paintable) for trim and baseboards; polyurethane or hybrid for exterior and moving joints.
- Clean and dry the joint, and remove old caulk completely. New caulk does not stick to old caulk or soap scum.
- Cut the nozzle at 45° so that the opening is a little smaller than the joint, and tool the bead smooth with a wet finger or a tooling spatula, within a few minutes.
- Painter's tape on both sides makes a crisp line. Pull it off before the caulk skins over.
- Check the cure time before water or paint touches it: silicone can need 24 hours, and paintable latex caulk about 2 hours before painting.
Tools & materials for this project
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Frequently asked questions
How many tubes of caulk do I need?
Divide the joint length by how many feet one tube covers (about 24 ft for a 1/4 × 1/4 in joint) and round up. For a typical bathtub of 12 ft of seam, a single tube is enough.
How far does a tube of caulk go?
About 24 ft of a 1/4 × 1/4 in bead from a standard 10.1 oz cartridge, or about 97 ft of a thin 1/8 × 1/8 in bead.
How much caulk for a window?
A 3 × 5 ft window has 16 ft of perimeter, so a 1/4 in bead takes about two-thirds of a standard tube.
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Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.