Caulk Calculator
This caulk calculator tells you how many tubes of caulk or sealant you need for a job. Enter the total joint length, the joint width and depth, and the tube size, and the caulk calculator returns the number of tubes, the linear feet per tube, and the volume of caulk, with a waste allowance built in.
Results
The Caulk Calculator is part of our Materials Estimating collection. Browse more materials estimating to size, convert, and check your work alongside this tool.
What the caulk calculator does
A caulk joint is a long, thin prism, so its volume is length times width times depth. The caulk calculator works out that volume, adds a waste allowance for tooling and cleanup, and divides by the volume of one tube: 10.1 fl oz for a standard cartridge, 20 fl oz for a sausage pack, or 28 fl oz for a large cartridge. It also shows the caulk coverage per tube in linear feet for your bead size.
Caulk coverage formula
Convert the length to inches, find the volume, and divide by the tube volume:
One US fluid ounce is 1.805 cubic inches, so a 10.1 oz tube holds 18.23 cu in, a 20 oz sausage 36.09 cu in, and a 28 oz tube 50.53 cu in. Linear feet per tube equals the tube volume divided by width × depth × 12.
Caulk calculator example
Sealing 100 ft of joints with a 1/4 × 1/4 in bead, 10.1 oz tubes, and 10% waste:
Each tube covers about 24.3 linear feet at that bead size. For 60 ft of 3/8 × 3/8 in joints with 28 oz tubes, the caulk calculator returns 3 tubes at 29.9 ft per tube.
How to use the caulk calculator
Add up the length of every joint in feet: window and door perimeters, trim, tub and shower lines, or expansion joints. Enter the joint width and depth in inches as decimals, such as 0.25 for 1/4 in or 0.375 for 3/8 in. Pick the tube size and a waste allowance, 10% is typical, then press Calculate. For a simple bead along a corner, use the bead size for both width and depth.
Reading caulk coverage per tube
The tube count is rounded up so you do not run short mid joint. The linear feet per tube shows how fast the bead size eats material: doubling both width and depth cuts coverage to a quarter, so a 1/2 × 1/2 in joint takes four times the caulk of a 1/4 × 1/4 in joint. Buy one extra tube for touch ups if the color must match, since batches can vary slightly.
When to use a caulking calculator
- Estimating sealant for windows and doors
- Pricing a bathroom or kitchen recaulk
- Ordering sealant for concrete and siding expansion joints
- Comparing cartridges with sausage packs for a big job
- Checking how far a single tube will go
Common caulk calculator mistakes
- Entering inches as feet. Joint length goes in feet; width and depth in inches.
- Using fractions. Enter 0.25 for 1/4 in and 0.375 for 3/8 in.
- No waste allowance. Tooling and cleanup use about 10%.
- Filling deep gaps solid. Use backer rod and enter the sealant depth.
Tips for a clean caulk coverage
- Cut the nozzle at 45° to the bead width you want.
- Tape both sides of the joint for straight edges.
- Tool the bead within a few minutes, before a skin forms.
Caulk coverage and joint design
Sealant works best when the joint has the right shape. For joints up to about 1/2 inch wide, make the depth equal to the width with a minimum of 1/4 inch. For wider joints, keep the depth about half the width and no more than 1/2 inch. A joint that is too deep stiffens the sealant so it tears when the gap opens and closes; a joint that is too shallow pulls away from the sides. Closed cell backer rod pressed into the joint sets the depth and stops the sealant from bonding to the back, so it only grips the two sides. That shape also saves material: filling a 1/2 inch wide, 1 inch deep crack solid takes twice the caulk of the correct 1/4 inch depth over backer rod. Enter the finished depth, not the depth of the gap, in the caulk calculator. When a job pairs sealant with tile, the grout calculator covers the rigid joints and caulk goes at the corners and changes of plane.
Sealant coverage calculator tips for each product
Acrylic latex caulk suits interior trim and paints well. Silicone suits wet areas and glass but does not take paint. Polyurethane and hybrid sealants suit exterior siding, concrete, and expansion joints, where movement is larger. Sausage packs in a barrel gun cost less per ounce and waste less packaging on big exterior jobs, while 28 oz cartridges suit construction adhesive and large joints. Check the label for the joint movement rating, often plus or minus 25% or 50%, and pick a product rated for the movement you expect.
Caulk coverage chart
Linear feet per tube for common bead sizes, with no waste allowance:
| Joint width × depth | 10.1 oz tube | 20 oz sausage | 28 oz tube |
|---|---|---|---|
| 1/8 × 1/8 in | 97.2 ft | 192.5 ft | 269.5 ft |
| 3/16 × 3/16 in | 43.2 ft | 85.6 ft | 119.8 ft |
| 1/4 × 1/4 in | 24.3 ft | 48.1 ft | 67.4 ft |
| 3/8 × 3/8 in | 10.8 ft | 21.4 ft | 29.9 ft |
| 1/2 × 1/4 in | 12.2 ft | 24.1 ft | 33.7 ft |
| 1/2 × 1/2 in | 6.1 ft | 12.0 ft | 16.8 ft |
Caulk Calculator FAQ
How much caulk do I need?
Multiply the joint length in feet by 12, by the width, and by the depth in inches to get cubic inches, add 10% waste, and divide by 18.23 for 10.1 oz tubes.
How many linear feet does a tube of caulk cover?
A standard 10.1 oz tube covers about 24 ft with a 1/4 inch bead, about 43 ft with a 3/16 inch bead, and about 97 ft with a 1/8 inch bead.
How much caulk for a bathtub?
A standard 60 inch tub set against three walls has about 10 ft of joint, so one 10.1 oz tube with a 1/4 inch bead covers it with room to spare.
Do I need backer rod?
Yes for joints deeper than about 1/2 inch. Backer rod sets the depth, saves sealant, and helps the joint flex without tearing.