1497
Caulk chart
Put your length and coverage per tube in: 100 linear feet at 30 feet per tube needs 3.33 tubes exact, order 4.
★ CONSTRUCTION · CAULK · COVERAGE CHART
Caulk Chart: 4 Tubes for 100 Feet at 1/4-Inch Bead
On the defaults — 100 linear feet at 30 feet per 10-ounce tube — you need 3.33 tubes exact, so order 4 tubes. This is the LENGTH version — feet of joint divided by feet per tube, with a lookup table for every common length — the caulk-coverage-chart page is the BEAD-SIZE version — feet per tube by bead width and depth; the paint-chart page is the PAINT version — the same divide-and-round-up model counted in gallons; and the drywall-chart page is the SHEET version — the same model counted in sheets.
What does 3.33 tubes, order 4, mean?
It means that 100 linear feet of joint, sealed with a bead that gives 30 feet per tube, need three full tubes plus a third of a fourth — and because tubes are sold whole, you order 4. The rounding is the whole story in miniature: a partial tube cannot be bought in the quantity needed, so any fraction, however small, becomes a whole tube. The part people get wrong is rounding to the nearest tube instead of up: 3.33 rounded to the nearest is 3, and 3 tubes cover only 90 feet, leaving 10 feet unsealed. The other part people get wrong is the exact fit: 90 feet need exactly 3.00 tubes, and order exactly 3, because the rounding is up to the next whole tube, not up plus one — an exact fit needs no spare tube from the rounding, though a spare for touch-ups is a separate decision.
Three things to check before you trust the number
Is 30 feet per tube right for your bead? Thirty feet per tube is the 1/4-inch bead figure used on this page, and published figures for a 1/4-inch bead vary with bead depth and product, roughly from the mid-twenties to about 30 feet. If your bead is wider, one tube covers fewer feet: the 15-feet-per-tube branch needs 6.67 tubes exact, order 7, for the same 100 feet. Enter your own feet-per-tube figure if your bead is not 1/4 inch, rather than trusting the default for a wider joint.
Did you measure every joint? The length entered here must be the total of all joints, not the longest single run: a room with four 25-foot walls has 100 feet of joint, not 25. The 50-foot branch needs 1.67 tubes, order 2, against the 3.33-tube headline, so missing one wall understates the order by a whole tube or more. Walk every joint — windows, doors, baseboards, tubs — and add them before dividing.
Are you counting waste, or just the joint? This page divides the measured length by the coverage figure with no extra waste allowance, because the coverage figure already assumes a consistent bead. Rough surfaces, overcut nozzles and starts and stops all use more sealant than a perfect bead, so a job with many short runs may need a spare tube beyond the order column. The order column is the exact math; a spare tube is insurance, and the two should not be confused.
Worked example
On the defaults: 100 linear feet, 30 linear feet per tube.
- Exact tubes: 100 ÷ 30 is 3.33 tubes.
- Order: 3.33 rounded up is 4 tubes — the 0.33 is a third of a tube that must be bought whole.
- Check: 4 tubes cover 120 feet, which is more than the 100 feet needed; 3 tubes cover only 90 feet, which is not enough.
And the other way: the length needing exactly 3.33 tubes at 30 feet per tube is 100 linear feet, and the coverage needing exactly 3.33 tubes over 100 linear feet is 30 linear feet per tube. A 30-foot job orders exactly 1 tube, and a 60-foot job orders exactly 2.
Every branch, checked
- 50 linear feet, 30 feet per tube: 50 linear feet, 30 feet per tube: 1.67 tubes exact — order 2 tubes.
- 150 linear feet, 30 feet per tube: 150 linear feet, 30 feet per tube: 5.00 tubes exact — order 5 tubes.
- 200 linear feet, 30 feet per tube: 200 linear feet, 30 feet per tube: 6.67 tubes exact — order 7 tubes.
- 90 linear feet, 30 feet per tube: 90 linear feet, 30 feet per tube: 3.00 tubes exact — order 3 tubes.
- 100 linear feet, 15 feet per tube: 100 linear feet, 15 feet per tube: 6.67 tubes exact — order 7 tubes.
The reverses, worked backwards
- Length needing exactly 3.33 tubes at 30 feet per tube: 100 linear ft — at 100 linear ft the figures are 3.33 tubes exact — order 4 tubes.; at the lower neighbor the figures are 3.00 tubes exact — order 3 tubes.; at the upper neighbor the figures are 3.67 tubes exact — order 4 tubes..
- Coverage needing exactly 3.33 tubes over 100 linear feet: 30 linear ft per tube — at 30 linear ft per tube the figures are 3.33 tubes exact — order 4 tubes.; at the lower neighbor the figures are 4.00 tubes exact — order 4 tubes.; at the upper neighbor the figures are 2.86 tubes exact — order 3 tubes..
What the defaults assume
The defaults are 100 linear feet and 30 linear feet per tube, so the headline is a 10-ounce tube laid in a 1/4-inch bead. The model is a division and a ceiling: exact tubes are length divided by coverage per tube, and the order rounds exact tubes up to the next whole tube, with a 1e-12 epsilon so an exact whole number orders exactly that many. The length reverse is checked at 10 feet either side, because 10 feet over 30 feet per tube is about 0.33 tubes; the coverage reverse is checked at 5 feet either side, because 100 over 25 is 4.00 tubes and over 35 is 2.86. The model does not include waste beyond the coverage figure, bead depth variation along the joint, primer, backer rod, or tools — count those separately.
Lookup table: tubes by length
Each row uses the 1/4-inch bead baseline of 30 linear feet per tube: exact tubes are the length divided by 30, and the order column rounds up. A row that lands exactly on a whole number orders exactly that many — no extra tube is added for an exact fit. For a wider bead, enter your own feet per tube in the calculator above: a wider bead covers fewer feet per tube, so the order rises.
| Length | Bead size | Coverage per tube | Exact tubes | Order |
|---|---|---|---|---|
| 10 linear ft | 1/4 inch | 30 linear ft per tube | 0.33 | 1 tubes |
| 20 linear ft | 1/4 inch | 30 linear ft per tube | 0.67 | 1 tubes |
| 30 linear ft | 1/4 inch | 30 linear ft per tube | 1.00 | 1 tubes |
| 45 linear ft | 1/4 inch | 30 linear ft per tube | 1.50 | 2 tubes |
| 60 linear ft | 1/4 inch | 30 linear ft per tube | 2.00 | 2 tubes |
| 75 linear ft | 1/4 inch | 30 linear ft per tube | 2.50 | 3 tubes |
| 90 linear ft | 1/4 inch | 30 linear ft per tube | 3.00 | 3 tubes |
| 100 linear ft | 1/4 inch | 30 linear ft per tube | 3.33 | 4 tubes |
| 120 linear ft | 1/4 inch | 30 linear ft per tube | 4.00 | 4 tubes |
| 150 linear ft | 1/4 inch | 30 linear ft per tube | 5.00 | 5 tubes |
| 180 linear ft | 1/4 inch | 30 linear ft per tube | 6.00 | 6 tubes |
| 200 linear ft | 1/4 inch | 30 linear ft per tube | 6.67 | 7 tubes |
| 240 linear ft | 1/4 inch | 30 linear ft per tube | 8.00 | 8 tubes |
| 300 linear ft | 1/4 inch | 30 linear ft per tube | 10.00 | 10 tubes |
| 360 linear ft | 1/4 inch | 30 linear ft per tube | 12.00 | 12 tubes |
| 480 linear ft | 1/4 inch | 30 linear ft per tube | 16.00 | 16 tubes |
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Exact tubes | length ÷ coverage per tube | 3.33 tubes — 100 ÷ 30. |
| Order | exact tubes rounded up | 4 tubes — 3.33 rounds up. |
| Length needing exactly 3.33 tubes | exact tubes × coverage per tube | 100 linear ft — 3.33 × 30. |
| Coverage needing exactly 3.33 tubes | length ÷ exact tubes | 30 linear ft per tube — 100 ÷ 3.33. |
| Feet covered by the order | order × coverage per tube | 120 linear ft — 4 × 30, more than the 100 needed. |
| Feet short on one fewer tube | length − (order − 1) × coverage per tube | 10 linear ft — 100 − 3 × 30, which is why rounding down fails. |
| 50 linear feet, 30 feet per tube | same model | 1.67 tubes exact — order 2 tubes. |
| 150 linear feet, 30 feet per tube | same model | 5.00 tubes exact — order 5 tubes. |
| 200 linear feet, 30 feet per tube | same model | 6.67 tubes exact — order 7 tubes. |
| 90 linear feet, 30 feet per tube | same model | 3.00 tubes exact — order 3 tubes. |
| 100 linear feet, 15 feet per tube | same model | 6.67 tubes exact — order 7 tubes. |
| Length needing exactly 3.33 tubes at 30 feet per tube | reverse | 100 linear ft: 3.33 tubes exact — order 4 tubes. |
| Coverage needing exactly 3.33 tubes over 100 linear feet | reverse | 30 linear ft per tube: 3.33 tubes exact — order 4 tubes. |
| 30 linear feet | same model | 1.00 tubes exact — order 1 tubes. |
| 60 linear feet | same model | 2.00 tubes exact — order 2 tubes. |
| 0 linear feet | same model | 0.00 tubes exact — order 0 tubes. |
| Negative length | same model | Length — 0 or more. |
Who uses this
- A DIYer sealing a bathroom — 100 feet at 30 feet per tube is 4 tubes, with the lookup table covering every other length without re-measuring.
- A contractor ordering for a job — the branches show how the order moves with length and bead size, so a wider exterior bead is repriced before ordering.
- A homeowner comparing sealants — the 15-feet-per-tube branch shows what a wider bead really costs in tubes, before the job starts.
- An estimator checking a quote — the reverses recover the length or coverage behind any quoted tube count, which checks a quote without re-measuring the job.
Accuracy & limitations
Figures are the model’s own arithmetic on the numbers you type, computed from unrounded values and displayed rounded HALF_UP to 2dp, with orders rounded up using a 1e-12 epsilon so exact fits are not over-ordered. The main limitation is the coverage figure, not the arithmetic: published feet-per-tube figures for a 1/4-inch bead vary with bead depth, product and application, roughly from the mid-twenties to about 30 feet, so check your product and enter your own figure when your bead differs. This page is a calculation tool, not trade advice — follow the sealant maker’s instructions for joint preparation and bead size.
Cite this calculator
100 linear feet at 30 feet per 10-ounce tube needs 3.33 tubes exact: order 4 tubes. Source: Bright Side Kit, https://brightoolbox.com/caulk-chart/, accessed 29 October 2026.
Frequently asked questions
How many linear feet does one tube of caulk cover?
At a 1/4-inch bead, this page uses 30 feet per 10-ounce tube, which sits at the top of the published range for that bead — other sources put a 1/4-inch bead nearer 25 feet, depending on bead depth. If your bead is deeper or your product differs, enter your own feet-per-tube figure: the calculator divides by whatever you enter, so the answer stays honest for your bead.
Why does a wider bead cover fewer feet?
Because a wider bead uses more sealant per foot: doubling the bead width roughly quadruples the cross-section when depth grows with width, so the same tube runs out much sooner. The 15-feet-per-tube branch shows the effect — the same 100 feet need 7 tubes instead of 4 — which is why bead size, not just length, decides the order.
Why round up instead of to the nearest tube?
Because a partial tube cannot be bought in the quantity needed, and rounding down leaves joint unsealed: 3.33 tubes rounded to the nearest is 3, and 3 tubes cover only 90 of the 100 feet. Rounding up guarantees the whole length is covered; the extra fraction is the price of buying whole tubes.
What if the exact figure is already a whole number?
Then you order exactly that many: 90 feet need exactly 3.00 tubes and order 3, not 4, and 60 feet order exactly 2. The epsilon in the rounding protects exact fits, so a job that lands on a whole number is not charged an extra tube for nothing.
Should I buy a spare tube beyond the order?
That is a separate decision from the order column: the order column is the exact math for the measured length, and a spare covers rough surfaces, overcut nozzles and touch-ups. On a job with many short runs, one spare is cheap insurance; on a single long straight run, it is usually unnecessary.
How do I measure the length to enter?
Measure every joint you intend to seal and add them: all four walls of a room, every window and door perimeter, the tub-to-wall joint, and any baseboard runs. Enter the total, not the longest single run, because the page divides the total by the coverage figure.