Reading the reel
How to estimate footage left on a cable reel
Partial reels rarely come with a reliable remaining length. The tag states what was shipped, not what is left, and the counter was on the puller, not the drum. Two practical methods get you close enough to quote.
Neither method needs special tools: a tape measure and a count of the wraps will do, and a scale helps if the reel is small enough to weigh.
Method one: wraps times average circumference
Count the visible wraps across the barrel (the cylindrical core between the flanges). Measure the diameter at the middle of the wound cable — halfway between the barrel and the outer layer — and multiply by 3.14 to get the average circumference. Multiply that circumference by the number of wraps.
Example: 40 wraps on a reel whose mid-layer diameter is 30 inches. Circumference is 94.2 inches, or 7.85 feet. Forty wraps is about 314 feet. Add roughly half a wrap for the loose end and call it 315 feet. That is close enough to quote, and it is what a buyer would estimate on sight.
Method two: weight difference
If the reel is small enough to weigh, subtract the empty reel weight (often stamped on the flange) and divide the remainder by the cable's weight per foot. Manufacturers publish weight per 1,000 feet, and the tag often shows the gross weight of a full reel.
This method is more accurate for large conductors and less accurate for small ones, where the reel itself dominates the total. It also requires knowing the tare weight, which is not always marked.
What to put on the form
Give your estimate and label it as an estimate. A buyer would rather see “about 300 ft, measured by wraps” than a precise number that turns out to be wrong. We confirm the remaining length at pickup, and the offer is adjusted if the estimate was far off in either direction.
Questions about this
How accurate is the wraps method?
Usually within ten percent on a partly used reel, which is enough to quote. Accuracy improves with a careful mid-layer measurement.
Can you measure footage at pickup?
Yes. Remaining length is confirmed during pickup, and the offer is adjusted if the estimate was materially wrong.
Does footage or weight matter more?
Footage, for anything priced on usable length. Weight matters mainly for transport planning and for mixed or unidentified material.