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New StandardGARAGE DOORS · OWNER-OPERATED · MIAMI
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Torsion SpringCalculator

Weigh the door with the springs unwound. Enter the numbers. Get the exact spring and the exact quarter turns — or use the turns chart below.

1 Weigh the door
2 Enter size & drum
3 Get spring + turns

The Door

Wind each spring
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Spring To Install

Exact Turns For Your Spring

Enter the spring you are actually installing and this solves the wind for it, rather than quoting a rule of thumb.

Squeeze the coils tight together, measure across 20 of them, and read it off the tape — this fills in the wire size for you.
Count what is on the shaft right now, not what you are buying. One spring carries the whole door, two split it — get this wrong and the verdict flips.

Springs Done Right

This is the same math I use on the job across Miami-Dade and Broward. I size the spring to your door — not whatever is closest on the truck — and back it with a 10-year warranty. Flat rate, out-the-door: $299 for a single torsion spring, $549 for a pair.

Call (786) 575-3463

⚠️ Safety first

Torsion springs store enough energy to cause serious injury or death. This calculator is for information only. Never loosen the set screws on a wound spring, and leave winding and replacement to a trained technician with proper winding bars.

Torsion spring turns chart

The rule of thumb: about one turn per foot of door height, plus about ¾ of a turn to keep the cables tight and the door up at the top. On a standard 4-inch (400-8) drum:

Door heightTurnsQuarter turns
6' 6"728
7'7.2529
7' 6"7.7531
8'8.2533
9'9.2537
10'10.2541
12'1248

Doors over 8 feet usually need larger (400-12 or high-lift) drums, which changes the count. The chart is a starting point; the calculator above solves for your exact spring.

How to measure an existing torsion spring safely

Only measure a spring that is broken or fully unwound, with the door closed. If you are not sure, have a technician measure it.

  1. Length: measure the coils only, not the cones. For a broken spring, measure both pieces and add them together.
  2. Wire size: squeeze 20 coils together and measure across them, then use the 20-coil helper above.
  3. Inside diameter: usually 1¾" or 2" on residential doors. It is often stamped on the winding cone.
  4. Wind direction: note which side of the center bracket the spring sits on. Left and right springs are not interchangeable.

Extension springs and conversions

This calculator is for torsion springs. Extension springs (the long springs that run along the tracks) are sized by door weight and height and replaced in pairs — see extension spring replacement. Converting from extension to torsion is often worth it on heavier doors; we quote both options.

Torsion spring calculator FAQ

How many turns does a 7 ft garage door need?
On a standard 4-inch (400-8) drum, a 7-foot door takes about 7¼ turns (29 quarter turns) on each spring. The exact number depends on the drum and the spring, so use the calculator above for your door.
How many turns does an 8 ft garage door need?
On a standard 4-inch (400-8) drum, an 8-foot door takes about 8¼ turns (33 quarter turns). Taller doors on 400-12 drums need more — see the turns chart.
How do I calculate the right torsion spring size?
Spring size depends on the door weight, height, drum size and how many springs the door uses. Enter those above and the calculator suggests a wire size, inside diameter and length. To match an existing spring, measure its length, wire size (20-coil method) and inside diameter.
Is there an extension spring calculator?
This calculator is for torsion springs. Extension springs are sized by door weight and height and sold in color-coded pairs; replace both together. See extension spring replacement for help.
Can I convert extension springs to torsion springs?
Often, yes, especially on heavier doors. A conversion needs a torsion shaft, center bracket, drums and correctly sized springs. We quote both options so you can compare.
Is it safe to wind a torsion spring myself?
Torsion springs store enough energy to cause serious injury. This calculator is for information. Replacing or winding a spring should be done by a trained technician with proper winding bars.

Rather have it done right?

Flat rate, out-the-door: $299 for a single torsion spring replacement or $549 for a pair, with a 10-year spring warranty and a free 25-point inspection. 24/7 dispatch across Miami-Dade and Broward.

📞 Call (786) 575-3463

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