How do you calculate total tube footage for a coil build?

Multiply tubes required by cut length per tube, then divide by usable yield. For 500 tubes at 8 ft each and 85% yield: 500 x 8 / 0.85 = 4,705.9 ft of tube stock versus 4,000 ft of finished tube.

Why order more tube than the finished length?

Saw kerf, end crop, bend rejects and damaged tube all consume stock that never reaches the core. The 85% yield in the example adds a 705.9 ft loss allowance on top of the 4,000 ft theoretical footage.

What is a good usable tube yield in coil manufacturing?

Straight-cut tube runs commonly hit 92-97% yield; hairpin-bent or tight-radius work can drop to 80-88% from bend cracking and scrap. The 85% default suits a moderate-bend job; tune it from your own scrap logs.

How much scrap allowance does an 85% yield imply?

At 85% yield you lose 15% of pulled footage to scrap, which is the 705.9 ft allowance in the example. Track actuals — if real scrap runs lower, raise the yield input on the next order to avoid over-buying.

Should I include end trim in cut length or in yield?

Put the finished, in-core length in cut length and let the yield term absorb crop and kerf. Double-counting trim in both fields inflates the order. Keep cut length as the part you actually braze into the core.

How do I convert footage to coils or sticks to order?

Divide the required footage by the footage per coil or stick and round up. With 4,705.9 ft needed and, say, 1,000 ft coils, you order 5 coils — the partial coil is your working buffer against the planned scrap.

Heat Exchanger, Coil & Radiator Manufacturing calculator

Tube Length Usage Calculator

Tube length usage is the total footage of tube stock you must pull to build a core once cutting scrap, end trim and bending losses are included. Production planners and buyers use it to convert a tube count and cut length into a coil-stock purchase order without coming up short mid-run. The usable-yield term captures saw kerf, crop ends, bend rejects and the odd kinked tube, all of which mean you consume more raw footage than the finished tubes contain. Order to the theoretical length and the line stops; order to this number and you have just enough plus a defined scrap allowance.

What this calculator does

Estimate tube footage required for coils, radiators, condensers, evaporators, oil coolers, or tube bundles from tube count, cut length, and usable yield.
Use it before releasing a job, buying tube, or staging cut lengths when a shortage would stop finning, bending, expansion, brazing, or assembly.
It computes the gross tube footage to procure so that, after scrap and yield losses, you still have enough good tube to cut the required count at length.

Formula used

Required tube footage = tubes required × cut length per tube ÷ usable tube yield
Tube loss allowance = required footage - theoretical footage

Inputs explained

Number of tubes required for the build:
Finished cut length per tube:
Usable tube yield (good footage after scrap):

How to use the result

Use it when releasing a coil-stock purchase order or kitting material for a production run from a tube count and cut length.
It assumes one yield rate across the whole run; a mid-run process change, a bad coil, or a different bend pattern can shift actual yield away from the planned figure.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).

Common questions

How do you calculate total tube footage for a coil build? Multiply tubes required by cut length per tube, then divide by usable yield. For 500 tubes at 8 ft each and 85% yield: 500 x 8 / 0.85 = 4,705.9 ft of tube stock versus 4,000 ft of finished tube.
Why order more tube than the finished length? Saw kerf, end crop, bend rejects and damaged tube all consume stock that never reaches the core. The 85% yield in the example adds a 705.9 ft loss allowance on top of the 4,000 ft theoretical footage.
What is a good usable tube yield in coil manufacturing? Straight-cut tube runs commonly hit 92-97% yield; hairpin-bent or tight-radius work can drop to 80-88% from bend cracking and scrap. The 85% default suits a moderate-bend job; tune it from your own scrap logs.
How much scrap allowance does an 85% yield imply? At 85% yield you lose 15% of pulled footage to scrap, which is the 705.9 ft allowance in the example. Track actuals — if real scrap runs lower, raise the yield input on the next order to avoid over-buying.
Should I include end trim in cut length or in yield? Put the finished, in-core length in cut length and let the yield term absorb crop and kerf. Double-counting trim in both fields inflates the order. Keep cut length as the part you actually braze into the core.

Last reviewed 2026-05-12.