Inputs
Results
Total area
—
sq ft
Material area used
—
sq ft
Required rolls
—
ceiling to whole rolls
Tape length
—
ft
| Metric | Value |
|---|
Example Coverage per Roll
Typical rolls with 6 inch side lap and 6 inch end lap. Values show nominal and effective single‑roll coverage.
| Roll size (W × L) | Nominal area | Effective area with 6"/6" laps |
|---|
Formula used
Let L = project length, W = project width, A = net project area after obstructions. Let roll width/length be Rw/Rl. Side lap = S, end lap = E. Courses count (perpendicular to strip run) Nc = ⌈D⊥/(Rw−S)⌉. Pieces per course (along strip run) Np = ⌈D∥/(Rl−E)⌉.
- Total side seam length:
Lside = (Nc − 1) × D∥. - Total end seam length:
Lend = Nc × (Np − 1) × Rw. - Installed plastic area (including laps, before waste):
Ainst = A + S × Lside + E × Lend. - Total material area with waste:
Amat = Ainst × (1 + waste/100). - Rolls required:
Rolls = ⌈Amat / (Rw × Rl)⌉. - Fast alt method (edge‑agnostic): effective single‑roll coverage
Aeff = (Rw − S) × (Rl − E). ThenRollseff = ⌈A × (1 + waste/100) / Aeff⌉.
The grid‑based method accounts for seam lengths explicitly and usually yields a slightly different result than the fast method, especially on small rooms where edge benefits matter.
How to use this calculator
- Select units and orientation for how you’ll run the strips.
- Enter project dimensions or switch to direct area input.
- Add obstructions to subtract holes, posts, or openings.
- Specify roll dimensions and your side/end lap preferences.
- Set waste percentage for cuts, damage, and off‑roll leftovers.
- Press Calculate to see rolls, tape, and areas instantly.
FAQs
Common practice is about 6 inches for side laps and 6–12 inches for end laps. Always follow local code, manufacturer guidance, and project specifications.
Yes. The grid‑based method explicitly adds side and end lap areas from total seam lengths, then applies your waste percentage on top.
Tape length equals total side seam length plus all end seam lengths. Turn on “Double‑tape” to multiply this by two if you seal both sides or apply redundant runs.
Yes. Use the toggle “Enter total area directly.” If your space is irregular, measuring total area can be easier than modeling exact dimensions.
This tool targets floor coverage. For walls or vertical returns, add their areas separately or increase the waste percentage to cover upturns and detailing.
Thickness depends on exposure and code. Common films range from 6 to 20 mil. This calculator focuses on geometric coverage rather than performance rating.
Tips
- Smaller rooms benefit from “along width” if it reduces courses.
- Use larger rolls to cut seam count and tape length.
- Increase waste for cluttered spaces or heavy cutting around posts.
- Consider perimeter upturns and penetrations separately in your takeoff.
Export your results for submittals or purchasing.