How To Measure Bow String Length [Compound+Recurve]

This is the definitive guide on how to measure bow string length.

In fact, you will learn how to figure out bow string length all sorts of the bow from traditional to modern recurve.

If you want to know the best way to measure compound, recurve, or longbow string length, this is the ultimate resource for you.

Let’s dive in.

Table of Contents

Before We Start

Why Is It Necessary To Measure Correct Bowstring Length?

This one seems like a super obvious question. Why should you even bother to measure correct bowstring length in the first place?

As an archer, you might before come across the term brace height. If not, let me introduce it quickly.

Brace height is the measurement from the center of the string towards the deepest grip end. A tool like a T-square bow is used to determine this distance.

what is brace height
Understood what is brace height actually?

Brace height is an essential factor that determines lots of permanence issues. Like it determines optimal Length for strings. 

Either way, the optimal Length for bowstring helps you to achieve optimal brace height. Because long string length leads to low brace height. And vice-versa. Usually, more than 6″ brace height is regarded as long, and below is short.

So what?

To be honest higher or lower bow height has its own advantages and disadvantages.

Lower brace height offers high arrow velocity.


Simply because it allows drawing a bowstring in full Length, which enforces the string to shoot vigorously.

But do you know whenever you release a string, it hits your arm? Besides, do you know is it always best to enhance arrow shooting speed? What about the accuracy, and what if high shooting speed becomes less forgiving. And You Can’t Ignore about bowstring lifespan.

In contrast, a high brace height can’t offer as high as a lower brace height bow can. But, higher brace height increases “Forgiveness” and accuracy dramatically. There are in-depth explanations for this, which is out of this article’s scope, and I think that will put us aside from the main aspect of this post. If you like to read about the topic here, I’ve got you an excellent article from Outdoortroop.

From the above discussion, the main point I tried to point out is you can’t take advantage of any particular brace height unless you know the bow’s correct string length because adjusting brace height requires knowing the precise string length.

Obvious Question: Ways To Measure Bowstring Length

There are two ways to measure bowstring length.

  1. Manually Measure it.
  2. Or Measure using Amo length.

Let’s dive into these two ways.

How to measure bowstring length following the manual measuring method? The answer is pretty much self-explanatory. 

Measure it manually using the required tools and techniques.

But, what about determining the Length using AMO length?

“I don’t know what you mean by AMO length.”

If you are just starting Archery, I can guess you will answer like this. That’s why I’ve decided to explain briefly here What is AMO length.

So, What Is AMO Length Actually?

AMO stands for “Archery Manufacturers Organization.” “AMO length” is an ideal length used by Archery manufacturers organizations as a standard measurement to determine the bow’s length. “AMO length is usually 3 inches shorter than original Bow length. If the AMO length is 47 inches, then the bow’s actual length will be 50 inches.

Got it?


Alright, but what’s the best way to measure bow string Length?

Should you measure it manually or by Amo Length? Which method will yield you the best result?

Are you seeking this answer?

To answer the question, at first, I’ve to answer why should you even bother to measure manually?

The simple answer is, that sometimes Standard AMO labels are missing on the bow.

I would recommend sticking with the manual option.

Why the “AMO Length” Way, and what’s the problem with the manual approach?

Simply put, the manual method may have errors in contrast to the Standard AMO method, but it yields accurate results. But the advantage of the AMO method is its “easy to measure” feature.

How To Measure Recurve Bow String Length?

I’m going to tell you the answer in a moment. But before that, you must know about the tools required for the measuring process. Here is the list of tools required measuring for recurve string length.

Required Tools To Measure Bow String Length For Recurve

  • Measuring Tape
  • Bow press (Only requires measuring compound bow string)
  • A marker that will help you with marking and measuring

How To Measure A Recurve Bow String Length

There are two ways to measure a recurve bow string length. One is manually measuring string length, while the other is the standard AMO way. Both the process used to measure recurve bow string length. But, the one which yields the most accurate result is the manual method. Yet, the easiest way is the AMO Standard Method.

Method #1 Manual Way To Measure Recurve Bow String Length

It’s just a piece of cake to measure recurve bow string length manually. There is no such complexity involved in this process.

Here’s how to do it.

  1. Grab a measuring tape.
  2. Place the measuring tape on one string groove’s end to another.
  3. Mark the points.
  4. Take the measurements,

Look, I said it’s just a piece of cake to measure string length for recurve. Now tell me, isn’t that so?

However, you can do it another way. Curious to know about it?

You can take measurements of the string of your bow by taking measures from one end of the string groove to another end, as well as you can take measurements from tip to tip of your bow. But in this way, you have to subtract the extra Length. This Extra Length is the distance from tip to string groove.

In case you are not familiar with bow terms like groove or tip, I’m attaching a bow and string length diagram below.

How to measure recurve bow string length
Figure on How to measure recurve bow string length

Method #2 Using AMO Length To Determine Recurve Bow String Length

This is the easiest way to determine recurve or any kind of bowstring length. Without talking too much, I’m telling you how to do it.

  • Figure out where “AMO Length” is located.
  • Take the Length to subtract the number by 3 inches. 
  • The remaining Length would be your bowstring length.

How To Measure Compound Bow String Length?

There are two ways you can measure compound bow string length. One is the manual way, while another one is known as the “AMO Way.” The manual way requires a few steps to measure string length, whereas “AMO Way” doesn’t.

Required Tools

Method #1 Manual Way

Let’s start with the manual way. Unlike recurve bow, measuring string length manually for the compound bow is not that easy. There’s a little trick to calculate.

Figure Explaining Compound Bow String Length

So, how to measure compound bow string length? Compound bow string length is measured while it’s being stretched. The standard way to achieve that stretched condition is applying 100lbs of tension by placing loops over the ¼ inches diameter pin on Top limbs. You can use a tool like a bow press to do this. The measurements are taken from the outside of the pin to the outside of the pin.

Seems unclear?

Yes, I know it.

Follow these simple steps to measure compound bow string length most easily.

  1. Place your compound bow on the bow press.
  2. Compress it by applying 100 lbs of tension using the bow press.
  3. Use a marker to mark the string end.
  4. Now, Take the measurements.
  5. There you have it.

Many people suggest compressing compound bowstrings manually. But, that process is hazardous (Check here what people are saying). Buy a bow press and master how to use it; definitely, it is well worth it.

Method #2 AMO Way

Probably this method of measuring string length for a compound bow is easier than the manual way. Although measuring this way for a compound bow is not as easy as recurve but definitely much easier than the previous method.

The main obstacle associated with this method is that the compound bow often doesn’t come up with a clear AMO Length marked.

That’s the negative side of this method.

Let’s know how to measure the length this way.

Compound bow AMO level typically contains string length, weight, cable, and draw. These measurements usually are exact as the actual Length. Either way, if you don’t find Length on the AMO level but draw weight, then you can use the Draw length chart to figure out string length.

How to measure crossbow string length?

To measure crossbow string length, you need to apply 100 lbs of tension for 20 seconds. Now, you should measure the span of unstrung limbs from tip to tip. Then subtract 3″ from the length you just got. This subtracted length would be your recurve bow string length.

How To Measure Longbow String Length?

Longbow string length can be determined by using AMO Length. Many people also consider measuring manually. Both techniques have their own advantages and disadvantages. The easiest way is to use AMO Standard Length while the manual Procedure is more accurate.

I am going to tell you both of these methods one by one.

Keep Reading.

#1 Manual Method

Precisely this way, you can manually measure longbow string length.

  1. Lay your longbow down.
  2. Grab a measuring tape.
  3. Locate the string groove and take the measurement.

#2 AMO standard Method

The absolute Length for a longbow string is 3″ shorter than the standard AMO length. Find AMO level on your longbow or any traditional bow and subtract 3″ from the Standard AMO length.

There you have it. It’s as easy as that.


So far, I have talked about how to measure a bowstring length. I showed you all sorts of ways to measure string length for compound and recurve bows. Not only that but also even showed you how to measure string length for a longbow. I discussed why accurate string length measurements are critical to bow performance and the best way to measure bowstring.

In the end, I want to ask you a question which one of the methods do you like most seems easier to you? Comment below and let us know.


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