How to Make a Tin Can Phone

How to Make a Tin Can Phone

How to Make a Tin Can Phone


Making a tin can phone is a fun hands-on project that allows you to explore the science behind sound waves and vibrations. With just a few simple materials, you can build your own working telephone to talk with friends and family. The best part is that it actually works!

In this article, I will walk you through step-by-step instructions on how to make a tin can phone from start to finish. You’ll learn about the basic science behind these simple homemade devices and how to troubleshoot any issues with your own tin can phone. Let’s get started!

What You Need

To build a tin can phone, you will need the following materials:

  • 2 clean tin cans (preferably the same size) – These will become the bases for your telephone. Make sure to clean out any food residues.
  • Hammer and nail – To punch a hole in the bottom of each can.
  • Strong string (at least 15-20 feet long) – This will become the telephone line that carries sound vibrations between the cans. Some options are fishing line, twine, thin rope, etc.
  • 2 paper cups – These will be punched with holes and attached to the string at each end to protect the string from damage.
  • Scissors – To cut the string.

Optional items:

  • Decorative tape or markers – To decorate your tin cans with fun designs.
  • Super glue – To attach cups or other decorative items to the cans.


Follow these steps to assemble your own tin can phone:

1. Punch a Hole in Each Tin Can

  • Take one of the tin cans and use the hammer and nail to punch a hole in the center of the can’s bottom.
  • Push the nail through slowly by hammering gently. Be careful not to dent the sides of the can.
  • Repeat this process to punch an identical hole in the bottom of the second tin can.

2. Thread the String Through the Cans

  • Take your string and thread one end through the hole in the bottom of the first can.
  • Tie a large knot at the end of the string inside the can to secure it.
  • Repeat this threading process to string the second can. You should now have both cans attached to either end of the long string.

3. Add Paper Cups as Protectors

  • Take one paper cup and punch a small hole in the bottom.
  • Thread the string through the hole in the cup.
  • Use super glue or tape to attach the cup over the hole on the outside bottom of the can.
  • Do the same thing to attach a cup to the other can.

The cups will protect the string from fraying against the sharp edges of the cans.

4. Stretch Out the String

  • Unroll the string to its full length between the two cans.
  • You want the string pulled tight, not too loose or saggy.
  • Have a friend/family member hold one can while you take the other can and walk away to stretch out the string between you.

5. Decorate the Cans (Optional)

  • To make your homemade tin can phone look more fun, decorate the outside of the cans!
  • You can use colorful tape, markers, stickers, or paint to personalize the cans with designs.
  • Let your creativity run wild.

Your tin can phone is now fully assembled and ready to use!

How to Use Your Tin Can Phone

To talk with your tin can phone:

  • Make sure the string is pulled tight between the two cans.
  • Each person holds one can up to their ear.
  • Talk into the open end of your can in a normal voice.
  • Your sound waves will vibrate the string to transmit your voice to the other can.
  • Listen through the can to hear the other person’s response.
  • Take turns having a conversation by talking and listening through the cans!

It may take some trial and error to find the right string tension for a clear signal between the cans. If you’re having trouble hearing, try stretching the string tighter.

The Science Behind It

So how does this simple tin can telephone actually work? Here’s a quick overview of the science:

  • Your voice box causes vibrations as you speak into the open can.
  • These vibrations travel through the air and hit the bottom of the can.
  • The bottom of the can vibrates in response to your voice’s sound waves.
  • The vibrations travel down the string attached to the can.
  • At the other end, the string’s vibrations cause the bottom of the second can to also vibrate.
  • This recreates the sound waves of your voice to travel through the air into the listener’s ear!

Essentially, the vibrations of your voice get translated into physical vibrations along the string between the cans. The tin cans act like speakers converting vibrations into sound waves. This allows you to transmit your conversations through the string “telephone line”.

Troubleshooting Tips

If you are having problems hearing through your tin can phone, here are some troubleshooting tips:

  • Stretch the string as tightly as possible between the cans. Any slack can dampen the vibrations.
  • Make sure the ends of the string are securely attached inside the cans. Try knotting them if they are loose.
  • Use cans of the same size and type for the best sound transmission.
  • Replace the string if it becomes frayed or damaged.
  • Wind the string carefully to avoid tangles or kinks.
  • Bring the cans closer together if you still cannot hear well.
  • Speak slowly and clearly into the bottom of the open can.
  • Plug the ear not holding the can to screen out ambient noises.

With some minor adjustments, you should be able to get your homemade tin can phone working properly. The exact set up can take some optimization, so be patient.

Fun Variations to Try

Once you master the basic tin can phone, there are all sorts of fun ways to experiment:

  • Use cans of different sizes and types – juice cans, plastic cans, coffee cans etc. How does it impact the sound?
  • Experiment with different string types – different thicknesses, materials like twine or fishing line etc.
  • Try attaching plastic funnels or megaphones to the open ends of the cans to amplify the volume.
  • Add a third can in the middle of your phone line – does it still work?
  • Use extra long strings to make backyard tin can phones. See how far apart you can communicate.
  • Make multi-can phones with a whole network of friends. Where’s the limit?

So grab some tin cans and string and let your imagination run wild! Making your own tin can phone is one DIY science project you’ll want to use over and over.


I hope this guide provided you with a clear overview of how to make a simple tin can phone using basic household materials. The ability to talk between cans connected by a string is a fun demonstration of basic sound science and vibrations in action. With a bit of trial and error and some troubleshooting adjustments, you’ll be chatting it up in no time. So get creative in decorating your cans, and be prepared for some amusing long-distance conversations! Making your own functional tin can phone is a rewarding hands-on learning experience as well as a nostalgic blast from the past.