Calculator
Cable reel capacity calculator
Enter a reel's flange, drum and traverse and the cable's outside diameter to see how many feet fit. Add the length you need and the table checks every common reel size against it.
Layered capacity
2,492 ft
About 760 m of cable at level winding.
Common sizes against your cable
| Flange | Drum | Traverse | Holds | Your length |
|---|
How the numbers are worked out
Winding depth is half the difference between flange and drum, less the clearance: H = (F − D) ÷ 2 − c. The formula estimate is 0.262 × (H + D) × H × T ÷ d², the standard reel capacity formula, with every dimension in inches and the answer in feet. The layered figure counts whole layers (H ÷ d, rounded down) and whole turns per layer (T ÷ d, rounded down), then adds up each layer's length, which grows as the winding builds outward. The formula guide works through two examples by hand.
Getting good inputs
- Measure the cable's outside diameter over the jacket, not the conductor size.
- Measure traverse inside the flanges, and drum where it meets the flange.
- On old reels, measure rather than trusting the stencil; rebuilt drums drift.
- For metric cable, divide millimetres by 25.4 to get inches.
When the answer is "too thick"
If the cable is thicker than the winding depth, or the drum is bigger than the flange, nothing fits and the calculator says so. Try a larger flange or a smaller drum. Stiff cable also has a minimum bend radius, so a smaller drum may not be allowed even when the arithmetic works; check the cable maker's data sheet.
Planning a pull with the result
Contractors often use capacity backwards: a feeder run of known length must fit on one reel so the pull has no splice. Enter the run plus a working allowance for tails, terminations and slack at each pull box, then read down the table for the smallest size marked as fitting. Remember that the heavier the full reel, the bigger the payoff stand and lifting equipment it needs on site.
Re-spooling remnants
Shops that cut remnants off long reels can wind them onto smaller empties so the big reel goes back to its maker or into the buyback. A remnant of a few hundred feet seldom needs more than a 24 or 30-inch reel. Label each re-spooled remnant with its cable type, size and length, and it stays useful instead of becoming another half-empty reel at the back of the yard.
Other builds
The arithmetic is identical for plywood, plastic and steel reels; only the measured dimensions change. Spoked steel flanges still count edge to edge. Moulded plastic reels often have a tapered drum, so measure its diameter midway across the traverse. Wire rope packs tighter than jacketed cable, while braided hose, armoured umbilicals and flat cable pack worse, so adjust your margin accordingly.
Buying a reel that fits
Checked used reels are available in common sizes through the reel supply program and the buy reels pages. Use the button above to copy the sizes into the request, then choose what you want done and the product.
Questions
How accurate is the calculator?
It gives the most cable that fits with perfectly level winding. Real winding on a job site holds less, so leave a margin of ten percent or more.
Which figure should I use, formula or layered?
The layered figure. It counts whole layers and whole turns, which is closer to what really fits, especially with thick cable.
What clearance should I leave?
About 2 inches below the flange rim is usual. More for cable that must not be crushed when reels are stacked or strapped.
Can I ask for reels from the result?
Yes. The button copies the sizes into the request below; you still choose buy, sell or recycle and the product yourself.
Request a pickup or quote
Work order received
- Reference
- Request
Next we read what you sent, sort the reels by tag and condition, and come back with what we buy, where returnables go, and a pickup day for your corridor. If it helps, reply with a photo of the stack and the reel tags.