How to Measure Garage Door Springs without Risking Your Life

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In order to understand the extent of risk when you intend to measure garage door springs, I will tell you just this. A standard garage door weighs at least 200-300 pounds and the springs have the power to lift it or bring it down without letting it slam. That says it all of how tensed they are. And don’t forget that broken or not, springs might still be tensed.

Well, you say! ‘I just want to measure the springs and not replace them’. Well, I say! That’s dangerous too. And anyway, if you are not going to replace them yourself, why bother measuring them. One thing for sure is that garage door spring repair is not a recommended DIY work – due to spring tension.

Surprise!!! Extension springs are even more dangerous than torsion springs


Everybody is talking about how dangerous torsion springs can be and leave out of the equation the dangers of extension springs. Boy, don’t I have (bad) news for you!!! Extension springs are often more risky to mess with than torsion springs. Let me explain why.

Torsion springs are very heavy. They also need special winding bars or drills (depending on brand) in order to be released, adjusted, or replaced. And so, they make a loud banging noise when they break and they might cause serious injuries if you keep your face too close to their coils. They might hurt your fingers too.

With extension springs, you also run the risk of the known “flying” in the garage spring. That’s when they lack safety cables, which keep them in their position should they snap. So, if you try to release their tension, remove them, mess with the cable or the bottom bracket, you might get seriously injured. If they snap and fly, you might get hurt if you stand in their way.

You might think your torsion spring is free of tension because it is broken. But this might not be the case. If it is still wound, DO NOT touch the winding cone setscrews or the bolts of the stationary cone (which secure it to the anchor bracket).

What precautions to take if you want to measure springs

Now, if you insist on measuring your garage door springs, take precautions. The most important thing is to protect your face but you should also wear gloves. Since springs must be compressed when you measure the coils, you need to keep the garage door open. And that’s the only good thing in this task because springs are not as tensed with the door open as when the door is shut.

BUT, make sure to disconnect the opener and clamp the door so that it will not slide down. And as you try to measure the springs, keep your face in a distance as much as possible.

How to measure garage door springs

(For standard torsion springs and sectional extension springs)

  • Measure spring length

Garage door springs have coils and end parts. In spite of their differences, you only need to measure the length without the ends. You always measure unwound springs and if they are broken, measure the length of each broken piece from the coil on one end to the coil on the other end. Be careful with broken springs. You might believe they are not wound, but they most likely are. In other words, they are still tensed and might hurt you. You need to loosen the winding cone setscrews carefully in order to measure them, BUT ONLY IF THE SPRING IS NOT WOUND.

  • Calculate the wire size

This measurement indicates how thick spring coils are. You will need a caliper or tape measure. The caliper placed on one coil will show you its thickness in a decimal. If you use a tape measure, it’s easier to measure 10 or 20 coils together and check the wire size in the chart.

  • Measure the inside diameter

This is the space between the spring coils. You will still need to use the measure tape or caliper.

  • Check the ends

Most torsion springs have standard ends (but there are exceptions to the rule). In the case of torsion springs, there are cones (stationary & winding) on the ends and these usually come with the new springs.

For extension springs, you need to pay more attention to the ends. They are:

  • Double looped
  • Open looped, or
  • Clipped ends
  • Determine the wind – for torsion springs only

The wind is left or right, and this is the most confusing part when trying to figure out which ones you need. Typically, there is a right wind spring on the left part of the door and a left wind spring on the right side part of the door (viewing the door from inside).

The easiest (and safest) way to measure extension springs…

…is to not measure them at all. That’s if you are lucky to know the weight of your garage door. If not, it’s very difficult to calculate it. But perhaps it’s in the manual or you have written it down when you purchased your door. Or, the manufacturer can inform you based on model.

What to keep in mind when you want to replace springs

The most important reason why measuring and replacing garage door springs is not a task for you is that they are tensed. But there is a whole lot to them than just tension.

  • They are also connected with the cables and extension springs utilize pulleys too.
  • Not all springs are the same. And I am not referring only to the differences between extension and torsion springs – although it’s vital to know if your garage door needs extension or torsion springs. And if we are talking about torsion springs, is one enough? But there are also distinctions among the same type of spring depending on door type, lifting system, and brand.
  • If you don’t choose the perfect spring for the door, you might need to make some cable adjustments. And this is an extra and equally dangerous task.
  • Remember that each garage door type (roll up, sectional, one-piece etc.) would have a different type of spring.
  • If one extension spring breaks, the other will follow soon. So, it’s always best to replace them together.

The safest ways to measure springs is to let a tech do it or find the weight of your door and order springs based on that.


Alexia studied sociology at Essex University and did postgraduate studies at Sussex University in the media field. In Greece she worked for many years in printed and electronic media. She has written and illustrated the children's book "Little Bobby Steps Into the World", which is available on Amazon. Today she is spending endless hours with, regularly writes articles for websites in America and Europe, and is a top rated content writer on Upwork. Alexia has always been interested in interior design and has written relative content over the years.

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