# How Much Does a Disco Ball Weigh?

Trying to determine the right size disco ball for your party can be a difficult task.  You don’t want your disco ball to be so big that it overpowers your room and guests. On the flip side, you don’t want to have a tiny disco ball that fails to light up the dance floor and becomes the butt of every joke.

Size is only one factor. The other and equally important factor is the weight of a disco ball. Well then, how much does a disco ball weigh?

The weight of a disco ball varies largely by the dimensions of the ball, the material of the ball, the material of the rod and the material of the mirrors.  For a quality made, standard 16-inch disco ball, you can expect the weight to range between 12-18 pounds.

Perhaps you’re not very strong and installing a disco ball may be a significant burden to you.  Or you have fragile ceilings. Maybe you are going to have to lug this disco ball around from event to event and you need to know what protective case to buy.  Or, you’re unsure of what motor to get because you don’t know the weight of your ball?

Knowing the weight of the disco ball you’re working with or getting an education on this topic before you buy anything is time well spent.

## Materials and Dimensions of the Disco Ball, Itself

The majority of today’s disco balls are made from a styrofoam or polystyrene foam base.  There are many different ways you can measure the weight of this material but the easiest from a disco ball perspective is by the cubic foot.

The calculation for the weight of an object is:
Weight of Object = Volume x Density

Disco balls are in the shape of a sphere and to get the volume (cubic inches to translate into cubic feet) of a sphere, the formula is:

Volume of a Sphere = 1/6 x π x (diameter) ³

So, in the case of a 12” disco ball, the equation is:
Volume =  1/6 x π x 12³
Volume = (1/6 x 3.14) x (12 x 12 x 12)
Volume = (0.523) x (1728)
Volume = 904.77 cubic inches

Next, we need to multiply the volume by density and the measurement for the density of polystyrene is .001 lbs/in³.

Volume x Density = Weight of an Object
904.77 x .001 = .9047 lbs or approximately 14.47 ounces.

1 cubic foot is equivalent to 1728 cubic inches.

Other examples:
A 16” diameter polystyrene base disco ball is 1.24 cubic feet and would weigh 2.14 pounds.
A 20” diameter polystyrene base disco ball is 2.42 cubic feet and would weigh 4.18 pounds.
A 24” diameter polystyrene base disco ball is 4.18 cubic feet and would weigh 7.23 pounds.

Now, not every disco ball is made from styrofoam or polystyrene foam.

Plastics and fiberglass are also popular for the core of a disco ball.  The weight tends to be higher per cubic foot in comparison and will vary even more depending on the thickness of the material.  Most plastic and fiberglass balls are not solid to the core. Aside from the shell the rest of the ball is hollow.

## Material and Weight of the Threaded Rod in a Disco Ball

No stone left unturned.  It may seem trivial but we need to access the weight of a threaded rod, often called an eye bolt with nut, which runs through the middle of the ball.

Threaded rod material, again, can vary drastically from manufacturer to manufacturer.  The smaller the diameter of the ball, usually, the lighter (and cheaper) the material of the rod.  It’s relative, I suppose.

The basic metals used for disco ball rods are zinc-plated, stainless, or galvanized steel.

Typically, the rod length is about 2 – 2 and 5/8 inches longer than the diameter of the ball.

Example:
A 12” disco ball would have a rod length anywhere from 14” – 14 and 5/8”.
A 16” disco ball would have a rod length anywhere from 18” – 18 and 5/8”.

The chart below compares the weight of the three different steel material eye bolts with nut and washer as 12” in length:

Here is another comparison of the same materials at 18” in length (notice thickness increased by ⅛ inch), suitable for a 16” disco ball:

The rod helps support the structure of the ball, to ensure it is compact and tight and is used to hang the disco ball in the location of your choice.  The additional length on the bottom of the ball gets secured with a lug nut. The excess length on the top of the ball will have an eyelet which makes it able to attach to a chain or hook on a stand, ceiling or another hanging platform.

In a low-quality mirror ball, the manufacturer may substitute a mounting screw located on top instead of a threaded rod through the entire length of the ball.  Most DIY disco ball instruction videos will advise a mounting screw and while this can be done it’s not recommended. Only do this if the tiles you are using are extremely light otherwise this is a safety risk.

## Material and Weight of the Mirror Tiles on a Disco Ball

The last major factor in determining the weight of a disco ball is the reflective tiles that are used.

Drum roll…you guessed it, the weight will vary depending on the type of material you select to use for your tiles.

The most common reflective material used in high-quality disco balls produced by manufacturers is a real glass mosaic tile.  These tiles are usually .5” x .5” in size for disco balls 16” or smaller. For disco balls 20” and greater, the tile tends to increase in size to 1” x 1”.

To determine the weight of these tiles, we need to do some math and first come up with the actual surface area of a disco ball (sphere).

To find the surface area of a sphere, use this formula:
Surface Area = 4πr²

The radius is half the diameter of the sphere, so if we use a 16” disco ball as our example, the radius is 8.

Surface Area = 4 x π x 8²
Surface Area = 12.5663 x 64
Surface Area = 804.24 sq. inches
804.24 sq. inches is approximately 5.58 sq. feet.

Why is this important?  We’re still trying to determine how heavy self-adhesive, glass mirrors weigh.

We found the weight of a 23.5” x 23.5”, with .5” x .5” wide and .125” thick real glass mirror sheet is 6.33lbs or about 1.648 lbs. per sq. foot.  A 16” disco ball is 5.58 sq. feet (example above) so 9.2 lbs of .5” x .5” real glass squares would be required to construct.

This would not include any type of surface sealer, paint, glue or adhesive materials which would be minimal, but still contributes to the total weight of the ball.

As you can see, the bulk of the weight in a higher quality constructed disco ball is in covering the surface area with the tiles.

DIY disco balls tend to have lower-quality material such as metallic foil (purchased by the sheet), carnival mirror (extremely light), old compact discs cut into small squares (for you thrifty and patient crafters) and for those that are extremely desperate, aluminum foil.  The weight of this material is substantially less compared to real glass tiles.

For decorative only displays, ceramic tile is becoming more popular because of the array of colors that can be used outside of the traditional silver, gold or rose gold mosaics.  This is comparable in weight to real glass.

## Summary of the Weight of a Disco Ball

For a low-end quality 16” disco ball, the weight of each major material is:

• Polystyrene base = 2.14 pounds
• Zinc-plated steel eye bolt rod = 1.07 pounds
• Real glass mirror tiles = 9.20 pounds

The total would be 12.41 pounds plus some miscellaneous material like the adhesive of the mirror tiles.

Mark Plevyak

Thanks for reading! Throwing events can be overwhelming but to me one of the most thrilling and rewarding experiences. Since we all grew up in different decades, we can't always relate to iconic time periods of the past. There is so much to celebrate so if you are thinking of planning an event, plan a Retro one. And, if you're attending a party, ensure you relive it to the fullest. Party Unique!