How to Measure Biceps Size Without a Measuring Tape: The DIY Guide

According to the Centers for Disease Control and Prevention, the average bicep size for adult males and females varies with age, making it a common metric for fitness tracking. While a soft tape measure is ideal, knowing how to measure biceps size without measuring tape can be useful for quickly gauging progress using everyday household items. Whether you're tracking gains or simply curious, these alternative methods offer reliable results without the need for specialized equipment.

Quick Summary

This guide provides practical, easy-to-follow instructions for measuring your bicep circumference using alternatives to a standard tape measure. Explore how to use household items like string and a ruler, smartphone apps with augmented reality features, or even standard-sized objects to track your muscle growth accurately and consistently. Learn the right techniques for both relaxed and flexed measurements to assess your progress effectively.

Key Points

• String and Ruler: Use a piece of non-stretchy material and a ruler for the most accurate DIY bicep measurement without a tape measure.

• Relaxed or Flexed: Measure your bicep either relaxed or flexed, but stick to the same method for consistency when tracking progress.

• Smartphone Apps: Use augmented reality (AR) apps on your smartphone to create 3D body scans and track measurements digitally over time.

• Standard Objects: For a quick, rough estimate, you can use objects of a known length, such as a sheet of paper, to gauge your bicep's size.

• Consistency is Key: Regardless of the method you choose, always measure under the same conditions (e.g., same time of day, same arm state) for consistent tracking.

• Find the Widest Point: For both relaxed and flexed measurements, wrap the string or tape around the widest point of your bicep, typically halfway between your shoulder and elbow.

The String and Ruler Method

One of the most accurate and reliable methods for measuring your bicep without a tape measure is using a piece of non-stretchy string, yarn, or a shoelace along with a ruler or yardstick. This technique is simple, requires minimal tools, and provides a clear, measurable result.

How to use the string and ruler method

1. Find your materials: Grab a piece of string or a flexible phone charger cable, a pen or marker, and a standard ruler or measuring device with clear markings.
2. Prepare for measurement: Decide whether you want to measure your arm relaxed or flexed. For a flexed measurement, curl your arm up as if doing a bicep curl and tense the muscle. For a relaxed measurement, let your arm hang loosely at your side. The flexed measurement captures your muscle's peak size, while the relaxed measurement offers a truer representation of your arm's overall mass.
3. Wrap the string: Wrap the string snugly but not too tightly around the thickest part of your bicep. The widest point is typically midway between your shoulder and elbow. For a flexed measurement, ensure the string passes over the peak of the muscle.
4. Mark the overlap: Once the string is wrapped, use a pen to make a clear mark on the string where it overlaps itself. If you don’t have a pen, you can simply hold the exact spot with your thumb and forefinger.
5. Measure the string: Lay the string flat and measure its length from the end to the mark you made using your ruler. Record this measurement in inches or centimeters.
6. Repeat for consistency: To ensure accuracy, repeat the process two or three times and take the average of your measurements.

Using Smartphone Measuring Apps

In today’s tech-savvy world, your smartphone can serve as a surprisingly effective measurement tool. Several augmented reality (AR) and body scanning apps can help you get a reading of your bicep size.

How to use smartphone apps for measurement

1. Download a suitable app: Search your phone's app store for terms like “AR measure,” “body scanner,” or “body measurement app.” Examples include Bodymapp for iPhone or various AR ruler apps available for both iOS and Android.
2. Set up the environment: Find a space with good lighting and stand in a position that allows you to easily move your phone around your arm. Some apps require you to stand in a specific pose for a 3D scan.
3. Follow the app instructions: Open the app and follow the on-screen prompts. For a simple AR ruler, you’ll place the virtual ruler around your bicep using your phone's camera. For more advanced body scanning, you'll likely be asked to rotate around your body while the app builds a 3D model.
4. Take the measurement: The app will provide a digital measurement of your bicep circumference. Many apps also save a log of your measurements over time, making it easy to track progress and visualize changes.

Comparison of Bicep Measurement Methods

Feature	String and Ruler	Smartphone App	Comparison with Known Object
Accuracy	High, if performed carefully.	Varies by app; modern AR apps can be very precise.	Low, provides only a rough estimate.
Cost	Free (using household items).	Can be free or have a cost for premium features.	Free (using household items).
Ease of Use	Simple and straightforward.	Can be more complex depending on the app's features.	Very easy, but imprecise.
Flexibility	Measures relaxed or flexed.	Measures relaxed or flexed.	Limited to what the object can approximate.
Portability	Requires bringing items with you.	Your phone is always with you.	Can be done anywhere with a known object.

Approximation with Standardized Objects

If you need a rough estimate and have no access to a ruler, you can compare your arm to objects with a known length. While not as accurate as the string and ruler method, this can provide a ballpark figure for progress tracking.

How to use standardized objects for approximation

1. Find a reference object: A standard sheet of printer paper is 8.5 inches wide, and a dollar bill is 6.14 inches long. You could also use a credit card, which has a standard width.
2. Mark segments: Wrap a flexible item like a phone cord around your bicep and mark the circumference. Then, lay the cord out flat and use your reference object to measure it. For example, if your marked cord is longer than one sheet of paper but shorter than two, you know your bicep is between 8.5 and 17 inches.
3. Improve accuracy: For a better estimate, you can fold the paper into smaller, known segments (e.g., in half to get 4.25 inches) to gauge the leftover length more accurately.

Conclusion

Measuring your bicep size is an excellent way to track your fitness journey, and the absence of a measuring tape doesn't have to stop you. From the highly reliable string-and-ruler method to the tech-forward approach of smartphone apps and the quick approximation of standard objects, there are multiple alternatives available. By choosing the right method for your needs, you can consistently monitor your progress and stay motivated toward your health and fitness goals. Remember to use the same technique and measure at the same time of day for the most consistent and meaningful results. For further reading on standard body measurement techniques, the CDC offers insightful data on average circumferences for different age groups.

Frequently Asked Questions

What household items can I use to measure my bicep without a tape measure?

You can use several household items, such as a piece of string, yarn, a shoelace, or a phone charging cable. You will also need a ruler, yardstick, or a standard-sized object like a sheet of paper to measure the length of the string after wrapping it around your arm.

Is it better to measure my bicep relaxed or flexed?

Both relaxed and flexed measurements are valid, but they serve different purposes. A relaxed measurement provides a better indication of your overall arm size, while a flexed measurement shows the peak size of your bicep muscle. The most important thing is to use the same method consistently each time you measure to accurately track your progress.

How do smartphone apps measure bicep size?

Smartphone apps can measure your bicep size using augmented reality (AR) technology. By using the phone's camera, these apps can overlay a virtual ruler or generate a 3D model of your body to calculate circumference measurements. Some apps, like Bodymapp, are specifically designed for this purpose.

How accurate are DIY bicep measurements compared to using a tailor's tape?

While a tailor's tape measure is the most precise tool for this task, the DIY string-and-ruler method can be highly accurate if done carefully. Smartphone apps vary in accuracy depending on the technology and app quality. Using standardized objects for comparison offers the lowest accuracy and should only be used for rough estimates.

How often should I measure my biceps to track muscle growth?

To track muscle growth, it is recommended to measure your biceps every few weeks or once a month. Taking measurements too frequently might show minor fluctuations that aren't significant. Consistent timing and method are more important than frequent measurements.

Where exactly on my arm should I measure my bicep?

For an accurate measurement, you should measure around the thickest or fullest part of your bicep. This is typically found at the halfway point between your shoulder and elbow joints.

Can I use a construction tape measure instead of a tailor's tape?

Yes, you can use a rigid construction tape measure for DIY body measurements. While a flexible tailor's tape is ideal for wrapping around body parts, a construction tape can still work for measuring the length of a string or cord you use to wrap around your arm.