Calculator inputs
Formula used
The calculator estimates tape length by combining edge lengths, overlaps, and practical allowances.
| Base edge length | Rectangle: 2 × (L + W) | Circle: π × D | Custom: Total |
| Openings | Openings added = count × perimeter |
| Overlap | Overlap added = joins × overlap per join |
| Multipliers | Multiply by passes and by 2 when masking both sides |
| Waste | Final = raw × (1 + waste% ÷ 100) |
| Rolls needed | Rolls = ceiling(final ÷ roll length) |
Increase waste when surfaces are rough, wet, or dusty.
How to use this calculator
- Choose units and select a shape mode.
- Enter dimensions, or your total edge length.
- Add openings, extra borders, and overlap allowance.
- Select passes and decide if both sides are masked.
- Enter roll length, then calculate and download results.
Example data table
| Project | Mode | Inputs | Waste | Roll length | Estimated tape needed | Rolls |
|---|---|---|---|---|---|---|
| Raised bed border | Rectangle | L=2.4 m, W=1.2 m, passes=1 | 12% | 50 m | ~8.06 m | 1 |
| Round planter stripe | Circle | D=0.8 m, joins=6, overlap=0.1 m | 10% | 50 m | ~3.32 m | 1 |
| Greenhouse trim lines | Custom | Total=18 m, openings=4 × 0.6 m | 15% | 50 m | ~24.84 m | 1 |
These examples are illustrative; your project may need more allowance.