Duct tape procurement
Duct Tape Roll Requirement Calculator
Calculate usable tape demand from joint length, overlap and roll length, then round up to whole rolls.
Tape inputs
Percentage of effective run lost to overlap.
Treat overlap as a planning reduction in effective tape yield. Follow the selected tape manufacturer's installation instructions for actual lap requirements.
Enter joint length and roll size.
Roll requirement
Planning rolls
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—Joint length
—Effective yield
—Planning tape
—Allowance
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Calculation method
The joint length is divided by the portion of each roll that remains effective after overlap. The allowance is then applied and the final roll requirement is rounded upward.
Effective roll yield = roll length × (1 − overlap ÷ 100)
Planning tape = joint length ÷ effective yield × (1 + allowance ÷ 100)
Rolls = ceiling(planning tape ÷ roll length)
Planning tape = joint length ÷ effective yield × (1 + allowance ÷ 100)
Rolls = ceiling(planning tape ÷ roll length)
Worked example
With 500 m of joints, 50 m rolls and 25% overlap, effective yield is 37.5 m per roll. After an 8% allowance, the calculation requires 15 rolls.
Why roll length alone is insufficient
A 50 m roll does not necessarily produce 50 m of installed joint coverage when laps, cuts and application waste consume tape.
Frequently Asked Questions
Can overlap be zero?
Yes, mathematically.
Can the result be fractional?
The planning result is deliberately rounded up to whole rolls.