Caulk Calculator
Calculate caulk tubes needed from joint length, width, and depth.
Returns tube count for bathrooms, windows, siding, and expansion joints in any unit.
Caulk quantity is determined by the joint dimensions (width and depth) and the total linear feet to be sealed. Standard caulk tubes contain approximately 10 fluid ounces, and a simple formula tells you how many tubes to buy.
Volume per Linear Foot Formula:
Volume (cu in/ft) = Width (in) × Depth (in) × 12
Tubes Required:
Tubes = Total Volume (cu in) / 18.6
One 10 oz tube = approximately 18.6 cubic inches of caulk.
Worked example — bathtub surround: Perimeter of tub: 12 linear feet of joints Joint width: 0.25 inch Joint depth: 0.25 inch Volume/ft = 0.25 × 0.25 × 12 = 0.75 cu in/ft Total volume = 0.75 × 12 = 9 cu in Tubes = 9 / 18.6 = 0.48 → buy 2 tubes (always round up, having extra is essential)
Coverage by joint size (per 10 oz tube):
| Joint Width | Joint Depth | Linear Feet per Tube |
|---|---|---|
| 1/8" | 1/8" | 150 ft |
| 1/4" | 1/4" | 37 ft |
| 3/8" | 3/8" | 16 ft |
| 1/2" | 1/2" | 9 ft |
| 3/4" | 3/4" | 4 ft |
Caulk types by application:
| Application | Caulk Type |
|---|---|
| Bathtub / shower | Silicone (mold-resistant) |
| Window/door frames | Latex paintable |
| Baseboard / trim | Paintable latex |
| Exterior gaps | Polyurethane (paintable) |
| Gaps near heat sources | High-temp silicone |
Application tips: Never caulk a dirty or damp surface — adhesion fails within weeks. Clean with rubbing alcohol, let dry completely, then apply. A smooth, wet-finger tool pass produces a professional concave bead.