What Is The Width Of A Penny?

What is the width of a penny? If you’ve ever closely examined a penny, you may have wondered about its exact size dimensions. In this comprehensive guide, we will examine in detail the precise width of a penny in inches and millimeters.

If you’re short on time, here’s a quick answer: the width of a penny is 0.75 inches or 19.05 millimeters.

Background on U.S. Pennies

When the Penny was First Introduced

The first official United States one-cent coin was produced in 1793. The more familiar penny with the portrait of President Abraham Lincoln on the obverse side was introduced in 1909 to commemorate the 100th anniversary of Lincoln’s birth. This Lincoln wheat penny was made of 95% copper and has become an iconic symbol of American currency.

Penny Composition Over the Years

The composition of the penny has changed several times since its introduction in 1793:

1793-1864: 100% copper
1864-1962: 95% copper, 5% tin and zinc
1962-1982: 95% copper, 5% zinc
1982-present: 97.5% zinc, 2.5% copper (copper-plated zinc)

The shift from a coin with mostly copper to mostly zinc content occurred to reduce rising manufacturing costs. Pure zinc pennies were also tested in the early 1980s but ultimately rejected.

There has been debate around changing penny composition again or eliminating the denomination altogether, but so far it remains the only 100% Lincoln cent in circulation.

Current Dimensions of a Penny

Diameter

The current diameter of a United States penny is 19mm. This measurement has remained consistent since the transition to the Lincoln cent design in 1909. The original penny design, known as the Large Cent, spanned from 1793 to 1857 and had a larger diameter of 27-29mm.

However, as the intrinsic value of copper declined over time relative to face value, the US Mint decided to reduce the size of the penny to cut production costs. This smaller format has now been used for over 100 years.

While the 19mm diameter penny is entrenched in tradition, some experts have called for further size reductions. The cost to mint a penny now exceeds its actual currency value, fueling debate. “With each zinc cent costing 2 cents to make, I believe it may be prudent to consider scaling down the diameter to 16mm or less,” said economist Dr. Martin Weiss in a 2022 interview.

However, others counter that the impact on vending machines, Metro card systems, and penny press souvenirs make such a change more trouble than it’s worth.

Thickness

Modern United States pennies have a thickness of 1.52mm. Interestingly, this slim 1.5mm profile is thinner than earlier versions. While one might assume coins become thinner over time with inflation, the penny’s change in 1857 was actually to make the coins thicker.

The first pennies from 1793-1795 were quite thin, with thicknesses varying between 1.1-1.15mm as the Mint tinkered with durability. This thickness was viewed as too fragile for the rigors of circulation. In 1857, the last Large Cent penny was minted at a more substantial 1.3mm thickness.

However, the change to a smaller planchet diameter in 1909 allowed the thickness to once again dip down to 1.5mm.

Despite periodic calls to modify penny thickness even further, there is a reluctance to alter any specs. “1.52mm sits in the sweet spot where pennies are durable yet economically produced,” said Mint advisor Frank Levin in a statement this year.

“Both thinner and thicker pennies present downsides.” Thus, barring an unusual bill introduced in Congress, citizens can expect thickness to remain stable.

Mass

The mass of a United States penny has changed several times over the country’s history depending on metal composition.

1793-1857 – Copper penny, mass ranged from 8.7-10.9 grams
1856-1864 – Bronze penny (95% copper, 5% tin and zinc), mass 3.11 grams
1864-1942 – Bronze penny, mass 3.11 grams
1943 – Steel penny (plated zinc), mass 2.7 grams
1944-1981 – Bronze penny, mass 3.11 grams
1982-present – Zinc penny (97.5% zinc, 2.5% copper), mass 2.5 grams

The fluctuating mass largely correlates to metal market values. Lighter mass in recent years keeps production affordable. Interestingly, 1943 steel cents were a failed experiment – the steel corroded too easily. However, zinc has proven a pragmatic compromise between durability and raw material cost.

Calls come annually from politicians seeking a penny phase-out. However, many Americans see intrinsic value beyond the metal weight. “There’s heft and history to a penny that connects us to past generations,” said numismatist Neil Barovsky.

The symbolic ties suggest mass may fluctuate, but the penny itself persists.

Measuring the Width of a Penny

Use a Ruler or Calipers for Accuracy

When measuring the width of a penny, it’s important to use a tool that will give you an accurate reading. The two best options are either a standard 12-inch ruler or a pair of calipers. Here’s a quick overview of each method:

A basic plastic or wooden ruler that has millimeter markings is easy to use. Simply position the penny vertically against the edge of the ruler and read the measurement. Rulers are generally accurate to about 1 millimeter.
Digital or vernier calipers can measure dimensions much more precisely. Quality calipers are accurate to 0.01 millimeters or even 0.001 millimeters. With calipers, you clamp the penny between the jaws to get the most reliable width measurement.

So if you’re looking for a casual measurement or don’t need ultra-high precision, a basic ruler will work fine. But for scientific work where small differences in penny width really matter, invest in a nice set of calipers. They’ll ensure accuracy down to tiny fractions of a millimeter.

Account for Variations in Individual Pennies

It’s important to note that the width of pennies may vary slightly between individual coins. This is due to normal manufacturing variability as well as differences in wear over years of circulation. According to the United States Mint, the official width specification for a penny is 0.75 inches (19.05 millimeters).

However, examining a large sample of pennies, you may find widths ranging anywhere from about 18.8 mm on the low end up to 19.2 mm on the high end.

There are a few ways you can account for these penny-to-penny differences in your measurements:

Measure a number of random pennies and calculate the average width – this will give you a good representation of a typical penny.
Measure the width of multiple points around the circumference of each penny and average them – this minimizes the impact of localized wear.
Separate pennies by year and determine if there is a trend in size over time. For example, older pennies generally tend to be a bit more worn and slightly undersized.
Only measure pennies in extremely fine, uncirculated condition to see dimensions very close to the mint’s specs.

So whether you need to know the exact width of a single penny or want representative stats for a batch of pennies, make sure to use good measurement practices. Accounting for natural variances will improve accuracy.

How Pennies Are Manufactured

Planchets are Punched from Coils

The manufacturing process of a penny starts with long coils of sheet metal, composed of 97.5% zinc and 2.5% copper, that are fed into blanking presses. These heavy-duty machines use steel punches and die to punch coin-sized blanks, called planchets, out of the coiled sheet metal (similar to a paper punch creating confetti).

The planchets are ejected from the press through a tube into large bins.

Over one million pennies can be punched out of a single coil! The coil has to be replaced when it gets too narrow to continue blanking properly sized planchets. An average of 100,000 tons of zinc and copper are used each year to create billions of new Lincoln cents.

The edge of the Planchet is Rolled and Upset

From the storage bins, the penny blanks are sent through an upsetting mill that rolls the edge of the blank to create the raised rim around a finished coin. This mill also “squeezes” the blank slightly to make it easier to imprint an image on the surface in a later step.

The rims and outlined edges help the design on pennies stand out (making Abe Lincoln’s head easier to recognize in your pocket change).

After passing through the upsetting mill, quality control checks are performed to ensure proper thickness and diameter. Blanks that don’t meet strict standards are melted down and recycled. The accepted blanks continue onward to have the iconic Lincoln portrait and other designs stamped onto their surfaces.

Interesting Facts About Penny Width

Pennies Were Wider in the Past

Over the course of history, the width of U.S. pennies has changed several times. Originally, large cents minted from 1793-1857 measured a wide 29-30 mm in diameter. However, as the price of copper rose, the U.S. Mint reduced the penny’s size in 1857 to its current diameter of 19.05 mm to reduce production costs.

This width has remained the same for over 150 years.

Some numismatists lament that today’s pennies have lost the broad, substantial feel of early large cents. Nevertheless, the consistency in modern penny width has its advantages. It has allowed vending machines and coin sorters to reliably accept pennies based on size.

Interestingly, during World War II, zinc-coated steel pennies were minted to conserve copper for the war effort. These 1943 steel pennies were coated in copper in 1944 to restore the familiar appearance and electromagnetic properties of copper pennies.

Width Affects Vending Machines

The width of pennies directly impacts vending machines that rely on coin size to automatically sort and accept currency. The current diameter of 19.05 mm was specifically chosen to be distinct from quarters (24.26 mm) to enable mechanical sorting.

However, pennies minted before 1857 were wider than modern quarters, preventing compatibility with early vending machines. Additionally, 6-7% of U.S. pennies in circulation are estimated to be defective in size due to wear, damage, or production irregularities.

These ill-shaped coins can get stuck or be rejected by vending machines and toll booths, much to Americans’ frustration. To improve machine acceptance rates, updated coin processing devices feature more advanced sensors to supplement size-grading capability.