Caulk calculator: how many tubes do I need?
Add up the feet of joint you're sealing, pick the bead size, and see how many standard 10.1 oz tubes to buy. A bathtub is usually around 14 to 17 feet around; a window frame, inside and out, is often 30 feet or more.
- 3 bead sizes
- Waste included
- Standard 10.1 oz tubes
Assumes a round bead and about 10% waste. Wide or deep gaps take far more caulk; fill gaps deeper than 1/4 inch with backer rod first.
Do the job
How it works
A standard 10.1-ounce tube holds about 18.2 cubic inches of caulk.
One foot of bead uses the area of a round bead times 12 inches: for a 1/4-inch bead that's about 0.59 cubic inches, so a tube runs about 31 feet. A 1/8-inch bead goes about four times as far, and a 3/8-inch bead less than half as far.
Tubes = feet to caulk × 1.1 (for waste and restarts) ÷ feet per tube, rounded up.
About this tool
Who it's for
For tubs, windows and trim, when you're not sure one tube will do it.
Example
You enter16 feet around a tub at a 1/4-inch bead
You getOne 10.1 oz tube, with some left over.
What's different
- Works from bead size, which changes the answer more than anything else.
- Adds 10% for waste and restarts.
- Links to the recaulking guide.
Gotchas and tips
- Gaps wider than 1/4 inch need backer rod first.
- Practice a bead on cardboard.
- Buy a spare tube if it's your first time.
Privacy: Runs entirely in your browser. Nothing you type is sent to us, and anything it remembers is saved on this device only.
Built and maintained by the GrabTheHammer team, using the same time, cost and safety notes as our guides. Updated November 2026. Spot a problem? Tell us.
Caulk questions
How many feet does a tube of caulk cover?
A 10.1 oz tube runs roughly 30 feet at a 1/4 inch bead, about four times that at 1/8 inch, and around 14 feet at 3/8 inch. Your bead is rarely perfect, so buy a little extra.
How many tubes do I need for a bathtub?
Most tubs take one tube with some left over. Buy two if you've never caulked before; practice beads and restarts use more than you'd think.
What bead size should I use?
Match the bead to the gap. Most tub, sink and trim joints need about 1/8 to 1/4 inch. Gaps wider than about 1/4 inch need backer rod behind the caulk.
Should I use silicone or latex caulk?
Use 100% silicone, or a caulk labeled for kitchens and baths, around tubs, showers and sinks; it stays flexible and resists mildew but can't be painted. Use acrylic latex or siliconized latex for trim and other joints you'll paint. Check the tube: the label says where it works and whether it's paintable.