Caulk Coverage
Figure out how many tubes of caulk to buy by total length, bead size, and cartridge size. Bead width is the big driver — coverage falls with the square of bead size — so a 1/4" joint eats caulk far faster than a thin 1/8" bead. Includes an optional cost estimate.
Figure out how many tubes of caulk to buy. The catch most people miss: bead width dominates — because coverage falls with the square of bead size, one cartridge does dozens of feet of a thin trim bead but only a handful of feet of a fat joint. Enter your run length and bead size for a real tube count.
Total length to caulk
Add up the linear feet of every joint, gap, or seam you'll run a bead along. Measure each run and sum them — e.g., four sides of a window, or the base of a tub.
Bead / joint size
The width of the caulk line (and roughly its depth into the joint). This is the biggest driver — coverage falls with the SQUARE of bead size, so a 1/2" joint eats caulk ~16× faster than a 1/8" one. Match it to the gap you're filling.
Cartridge size
The tube you're buying. The 10.1 oz cartridge (for a caulk gun) is the standard. Squeeze tubes are small; sausages and 28 oz cartridges are for big jobs and pro guns.
Waste & cost
A waste buffer (always round up to whole tubes), plus an optional price for a cost estimate.
Waste allowance
Price per tube (optional)
Caulk Needed
3 tubes
24.3 ft per tube · covers 55 ft incl. waste
Bead width is the whole game
Coverage drops with the square of bead size, so a 1/2" joint uses caulk about 16× faster than a 1/8" one from the same tube. If you can back-fill a deep gap with backer rod and lay a shallower bead, you'll use far fewer tubes. This assumes a square joint fill (the standard chart basis) — a rounded surface bead of the same width goes a little further, so the count errs toward having enough.
Coverage = cartridge volume ÷ bead size² ÷ 12 (a square joint fill — the standard chart convention), rounded up to whole tubes with your waste buffer. Excludes surface prep, backer rod, and primer. Real coverage varies with joint shape, tooling, and gun control — keep a spare tube. Matches published manufacturer coverage charts (2026).
💡About this calculator▼
Buying caulk seems simple until you're standing in the aisle wondering whether one tube will do the whole job or whether you need six. The answer hinges on something most people underestimate: bead size. Because a bead of caulk fills a joint in two dimensions, coverage drops with the square of the bead width — so the same 10.1 oz cartridge that lays roughly 97 feet of a thin 1/8" trim bead covers only about 6 feet of a fat 1/2" joint. That's a 16-fold difference from one variable.
This calculator turns your project into a straight tube count. You enter the total linear feet you need to caulk (add up every joint, gap, and seam), pick your bead size and cartridge size, add a small waste allowance, and it tells you how many tubes to grab — rounded up to whole cartridges, because you can't buy a partial tube. Add a price per tube and it estimates the cost too.
The coverage math is the standard one manufacturers publish: cartridge volume divided by the joint cross-section. It reproduces published sealant coverage charts, so the numbers match what you'd get off a supplier's estimator — just tailored to your exact run length and bead. Round up, keep a spare tube, and you won't be making a second trip to the store mid-job.
The estimate is built from a coverage figure and your run length.
Step 1 — coverage per tube. A cartridge holds a fixed volume of caulk, and a bead of a given size uses a fixed amount per foot. Coverage (linear feet) = cartridge volume ÷ (bead size × bead size) ÷ 12, treating the joint as a square fill (width equal to depth) — the standard convention behind published coverage charts. For a standard 10.1 oz cartridge (about 18.2 cubic inches): • 1/8" bead ≈ 97 linear feet · 3/16" ≈ 43 ft · 1/4" ≈ 24 ft · 3/8" ≈ 11 ft · 1/2" ≈ 6 ft. Bigger cartridges cover proportionally more — a 20 oz sausage is roughly double a 10.1 oz cartridge.
Step 2 — add waste. Real jobs lose caulk to tooling, drips, partial beads, and the caulk stuck in a cut nozzle. The calculator adds your waste percentage (5% is the practical minimum; 10–15% is safer) to your linear feet.
Step 3 — round up to whole tubes. Tubes needed = your length-with-waste ÷ coverage per tube, rounded up, since caulk is sold by the tube. The result also shows your spare coverage (the extra feet the last, partial tube gives you) and, if you enter a price, the total cost.
📐How it's calculated▼
Tubes = ceil( linear feet × (1 + waste%) ÷ coverage per tube ).
Coverage per tube (linear ft) = cartridge volume (in³) ÷ bead size² ÷ 12, where cartridge volume (in³) = fluid ounces × 1.8046875.
Coverage for a standard 10.1 oz cartridge: 1/8" ≈ 97 ft · 3/16" ≈ 43 ft · 1/4" ≈ 24 ft · 3/8" ≈ 11 ft · 1/2" ≈ 6 ft
Optional cost = tubes × price per tube.
Worked example — 100 ft of a 1/4" bead, standard 10.1 oz cartridge, 10% waste:
→ Coverage = 18.2 in³ ÷ (0.25 × 0.25) ÷ 12 ≈ 24.3 ft per tube
→ Length with waste = 100 × 1.10 = 110 ft
→ Tubes = ceil(110 ÷ 24.3) = ceil(4.53) = 5 tubes (with ~11.5 ft of spare coverage)
The square-law is the thing to internalize: double the bead width and you quadruple the caulk used per foot.
📎Sources:PK Supplies — Sealant Estimator Chart (linear feet per cartridge by joint size),Everkem — Caulk Yield Calculator (cartridge/sausage sizes, minimum waste factor)
🔍Finding your inputs▼
Total length to caulk: Add up the linear feet of every joint, gap, or seam you'll run a bead along, and enter the sum. Measure each run and total them — for example, the four sides of a window frame, the perimeter where a tub meets the wall, or the length of baseboard along a floor. If you're caulking several identical things (say, ten windows), measure one and multiply. This is the length the bead follows, not the area of anything.
Bead / joint size: The width of the caulk line, which also roughly sets how deep it fills the joint. This is the single most important input because coverage changes with the square of it. Use 1/8" for thin trim lines and small gaps, 1/4" for common jobs like window frames and tub/tile edges, and 3/8"–1/2" for wide gaps and large joints. If you're unsure, look at the gap you're filling: match the bead to the gap width. Choosing a bead bigger than you need is the fastest way to burn through tubes.
Cartridge size: The tube you'll buy. The 10.1 oz cartridge that fits a standard caulk gun is by far the most common and the default here. Squeeze tubes (about 5.5 oz) are handy for tiny jobs without a gun. 20 oz sausages and 28 oz cartridges are for big jobs and professional guns and cover proportionally more per tube. Pick the size you actually intend to purchase so the tube count matches the shelf.
Waste allowance: Extra caulk to cover tooling, drips, partial beads, and the material left in a cut nozzle between sessions. Manufacturers suggest a 5% minimum; bump it to 10–15% if the joints are irregular, you're working overhead or in awkward spots, or you're not practiced with a caulk gun. It's cheap insurance against coming up one tube short.
Price per tube (optional): Enter what a single tube costs to get a total cost estimate; leave it at 0 to skip. Basic acrylic-latex caulk is inexpensive, while silicone, kitchen-and-bath, and specialty sealants cost more — use the price of the specific product you plan to buy.
⚠️Special situations▼
Why does a slightly bigger bead need so much more caulk?
Because caulk fills a joint in two dimensions, not one, so coverage falls with the square of the bead size, not in proportion to it. A bead that's twice as wide is also (roughly) twice as deep, so it uses about four times as much caulk per foot — and a 1/2" bead uses about sixteen times as much per foot as a 1/8" one. That's why the same 10.1 oz cartridge that lays close to 100 feet of a thin trim bead covers only about 6 feet of a big 1/2" joint. The practical takeaway is to use the smallest bead that properly fills and seals the gap. If you have a deep or wide gap, don't just lay a giant bead of caulk to fill it — that wastes material, cures poorly, and often fails; instead pack the gap first with foam backer rod (or, for very wide gaps, use an expanding foam or a different filler), then lay a modest caulk bead over it. You'll use far fewer tubes and get a better, longer-lasting seal.
How do I measure the linear feet if I have lots of small joints?
Measure each run and add them up — the calculator wants the total distance your caulk bead will travel, regardless of how it's broken up. For a window, that's the sum of all four sides of the frame you're sealing; for a bathtub, it's the length along each wall the tub touches; for baseboard, it's the length of each wall's base. If you have many identical items, measure one representative unit and multiply by the count: ten windows that are each 3 feet by 4 feet have a perimeter of about 14 feet each (2 × [3 + 4]), so roughly 140 feet total if you're caulking all four sides. Don't forget that some jobs only caulk certain edges — you might caulk the top and sides of a window but not the bottom, for instance. When you're not sure whether to count an edge, count it; the small overage just adds to your safety margin. Round each measurement up to the nearest foot as you go and the total will already have a little cushion built in.
Should I buy 10.1 oz cartridges or a bigger sausage/28 oz tube?
It depends on the size of the job and the gun you own. The 10.1 oz cartridge is the standard, fits every basic caulk gun, and is the right choice for typical household jobs — a few windows, a tub surround, some trim. For large jobs (a whole house of siding joints, extensive concrete or deck seams, a big remodel), a 20 oz sausage or a 28 oz cartridge covers proportionally more per tube, which means fewer tube changes mid-job and often a lower cost per linear foot. The catch is that sausage packs require a sausage gun (or a gun that accepts both), and 28 oz cartridges need a larger-capacity gun, so only go that route if you have or will buy the right applicator. There's also less waste with fewer tubes, since each cut nozzle strands a little caulk. For most DIYers doing an afternoon's worth of caulking, stick with 10.1 oz cartridges and buy one or two extra; for a big or repeat job, the larger formats pay off. The calculator lets you compare — switch the cartridge size and watch the tube count change.
Does the type of caulk (silicone, latex, etc.) change how much I need?
Not meaningfully for the quantity — coverage is driven by the volume in the tube and the size of your bead, and standard cartridges hold about the same volume regardless of whether they're acrylic-latex, siliconized latex, pure silicone, or polyurethane. So this calculator's tube count applies across caulk types as long as you're using a standard-size cartridge. What the caulk type does change is the **cost** (silicone, kitchen-and-bath, and specialty sealants cost more than basic acrylic-latex, so use the right price in the optional cost field) and the **suitability** for the job, which matters more than quantity: use a mildew-resistant silicone or siliconized formula for wet areas like tubs and showers, a paintable latex or acrylic for interior trim you'll paint over, an exterior-rated sealant for outdoor gaps and siding, and a specialized product for high-movement or structural joints. Match the caulk to the job first, then use the calculator to figure out how many tubes of that product to buy. A slightly different published coverage on a specific product's label is usually within this estimate's waste margin.
❓Common questions▼
How many linear feet does a tube of caulk cover?
It depends almost entirely on your bead size, because coverage falls with the square of the bead width. A standard 10.1 oz cartridge covers roughly 97 linear feet at a thin 1/8" bead, about 24 feet at a common 1/4" bead, about 11 feet at 3/8", and only about 6 feet at a fat 1/2" joint. In other words, the same tube can do anywhere from a handful of feet to nearly a hundred, purely based on how big a bead you lay. Larger tubes cover proportionally more — a 20 oz sausage is roughly double a 10.1 oz cartridge. These figures match published manufacturer coverage charts (coverage = cartridge volume ÷ bead size² ÷ 12, for a square joint fill). Enter your specific length and bead above for an exact tube count with a waste buffer.
How many tubes of caulk do I need for a project?
Take your total linear feet, add a waste allowance, and divide by the coverage per tube for your bead size — then round up. For example, 100 feet of a 1/4" bead at about 24 feet of coverage per 10.1 oz tube, with 10% waste, works out to 110 ÷ 24 ≈ 5 tubes. The three things that move the answer are the total length you're caulking, the bead size (by far the biggest factor), and the cartridge size you buy. Because you can only buy whole tubes and running out mid-job means a second trip, always round up and keep a spare. This calculator does all of that for you — enter your length, bead, cartridge size, and a waste percentage, and it returns the number of tubes (and the cost, if you add a price).
What size caulk bead should I use?
Match the bead to the gap you're filling — use the smallest bead that fully seals it. As rough guidance: a 1/8" bead suits thin trim lines and hairline gaps, a 1/4" bead handles most common jobs like window and door frames, tub and tile edges, and baseboards, and 3/8" to 1/2" beads are for genuinely wide gaps and large joints. Cutting the nozzle at a 45-degree angle and controlling the opening size lets you dial in the bead. The important thing to know is that going bigger than necessary wastes a lot of caulk (coverage drops with the square of bead size) and can actually seal worse, since a huge bead cures slowly and may crack or pull away. For a deep or wide gap, don't fill it entirely with caulk — pack it first with foam backer rod, then lay a normal-sized bead on top. You'll use far less caulk and get a more durable seal.
How much extra caulk should I buy for waste?
Plan on at least 5% extra, and 10–15% if the job is tricky. Manufacturers commonly recommend a 5% minimum waste factor to account for the caulk lost to tooling the bead, drips, uneven application, and the material that hardens in a cut nozzle between sessions. Bump that up toward 10–15% if you're caulking irregular or damaged joints (which swallow more), working overhead or in cramped spots, or if you're not experienced with a caulk gun and expect some do-overs. In practice, because you round up to whole tubes anyway, you'll often have a partial tube of cushion built in. The safest approach is to add the waste percentage in the calculator and then buy one extra tube beyond what it shows — leftover caulk stores reasonably well if you reseal the nozzle, and it's much cheaper than stopping a job to go buy one more tube.
Can I use this for both a caulk gun cartridge and a squeeze tube?
Yes — the calculator handles the common package sizes, so pick the one you're actually buying. The standard 10.1 oz cartridge (the kind that loads into a caulk gun) is the default and covers most projects. Small squeeze tubes (around 5.5 oz) are convenient for tiny touch-up jobs where you don't want to deal with a gun, and they cover proportionally less. For big jobs, 20 oz sausage packs and 28 oz cartridges cover proportionally more but require the matching gun. Because coverage scales directly with the volume in the package, the calculator adjusts the tube count automatically when you change the size — so you can compare, say, how many 10.1 oz cartridges versus 20 oz sausages a long run would take. Just make sure the size you select matches what's on the shelf and what your caulk gun accepts.
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