Dime Thickness & Size: Diameter in mm, cm and Inches

A standard modern U.S. dime is 1.35 mm thick, approximately 0.053 inches. Its diameter—the distance across its face through the center—is 17.91 mm, or approximately 0.705 inches.

The U.S. Mint's coin specifications list both measurements. They describe the modern U.S. coin, not every historical dime or a coin from another country.

For a quick mental reference, a dime is a little under 1.8 cm across and a little over 1 mm thick. Those are two different dimensions, so check which one a comparison requires.

The inch figures are calculated from the listed millimeter values using inches = millimeters ÷ 25.4. The Mint displays rounded inch measurements of 0.705 and 0.053 inches.

Because a dime is circular, its width and length across the center are the same diameter. When someone asks how tall it is, orientation matters: standing on its edge, it is 17.91 mm tall; lying flat, its listed thickness is 1.35 mm.

The measurements are published reference specifications. A worn, damaged or altered coin is not a precision gauge.

Use the face view to understand diameter and the edge view to understand thickness:

FACE VIEW                         EDGE VIEW
       .-------.                   +---------+
     /           \                 +---------+  1.35 mm
    |<--17.91 mm-->|
     \           /
       '-------'

Labeled schematic, not a scale drawing or an actual-size coin.

A picture of a dime does not automatically appear at its real physical size. Screen zoom, display settings and print scaling can all change it. For an actual-size check, use a real coin or measure 17.91 mm with a suitable measuring tool.

If you are comparing an object's width with a dime, look across the face. If you are comparing a narrow gap with a dime, the thickness is the relevant measurement.

The Mint publishes these dimensions for modern U.S. coins:

The dime is narrower and thinner than each of the other three coins in this table. Face value does not determine physical size: a penny is wider than a dime.

A quarter is 6.35 mm wider than a dime across its diameter, and 0.40 mm thicker. A nickel is thicker than the quarter even though its diameter is smaller.

These comparisons use the listed dimensions. They do not identify a coin's year, composition, condition or collector value.

How many millimeters thick is a penny?

A modern U.S. penny is 1.52 mm thick, according to the U.S. Mint's specifications. That is 0.152 cm, or approximately 0.05984 inches, commonly rounded to 0.060 inches.

The penny is 0.17 mm thicker than a dime: 1.52 − 1.35 = 0.17 mm. Its 19.05 mm diameter describes the distance across the face, not the thickness.

Two nominal penny thicknesses total 3.04 mm, close to but not exactly 3 mm. Actual stacked coins can differ because of wear, surface relief and alignment. These figures apply to the modern U.S. penny; a British penny or a historical coin needs its own specifications.

How thick is a nickel in millimeters and inches?

A modern U.S. nickel is 1.95 mm thick, according to the U.S. Mint's coin specifications. This is 0.195 cm, or approximately 0.07677 inches. The Mint rounds the inch value to 0.077 inches.

To convert the listed thickness, divide by 25.4: 1.95 ÷ 25.4 ≈ 0.07677 inches. The nickel's 21.21 mm diameter is the measurement across its face, not its thickness.

Compared with the dime's 1.35 mm thickness, a nickel is 0.60 mm thicker. It is also 0.20 mm thicker than the quarter listed above, despite having a smaller diameter.

A nickel is a close visual reference for two millimeters, but it is 0.05 mm thinner than 2 mm. Use the actual measured object or a suitable measuring instrument when a precise gap or fit matters.

What are the measurements of a U.S. quarter?

The U.S. Mint lists a modern quarter as 24.26 mm in diameter and 1.75 mm thick. That is 2.426 cm across and 0.175 cm thick.

Converted from those millimeter values, the diameter is approximately 0.9551 inches and the thickness is approximately 0.06890 inches. The Mint displays the rounded inch values as 0.955 and 0.069, respectively.

A quarter is slightly less than one inch across: 25.4 − 24.26 = 1.14 mm shorter in diameter. Its circular face is wider than a nickel's, but its edge is thinner, as the comparison table shows.

For an actual-size reference, measure 24.26 mm or use a real modern U.S. quarter. A coin picture on a screen may appear larger or smaller because of zoom and display settings. The word “quarter” here means the U.S. 25-cent coin; it does not mean a quarter-inch thickness.

A 5 mm length is about 27.9% of a dime's 17.91 mm diameter—a little over one-quarter of the distance across the coin.

The calculation is 5 ÷ 17.91 × 100 ≈ 27.9%. This is a comparison of lengths. A 5 mm circle would have a much smaller fraction of the dime's face area, so do not treat the percentage as an area comparison.

For thickness, 5 mm is about 3.70 times the dime's listed 1.35 mm thickness. Four nominal dime thicknesses total 5.4 mm, slightly more than 5 mm.

A stack is only an estimate. Surface relief, wear, dirt and alignment can affect a real stack's height. Use a caliper for a close fit rather than assuming the arithmetic gives the exact height of your coins.

“Dime-sized” usually describes a small circular patch roughly as wide as a dime: about 17.91 mm or 1.79 cm across.

That phrase does not define a fixed volume. Two blobs with the same width can contain different amounts if one is taller, thicker or a different shape. You cannot reliably convert a dime-sized amount into teaspoons, milliliters or grams from diameter alone.

For a non-volume thickness reference, compare the coin with a standard credit card's nominal 0.76 mm thickness. A dime's 1.35 mm thickness is about 1.78 times that value. This is a calculation from reference dimensions, not a measurement of two particular objects.

How wide is a dime in centimeters?

Its published diameter is 1.791 cm, commonly rounded to 1.79 cm.

Is a dime 1 mm thick?

No. The listed thickness is 1.35 mm, which is 0.35 mm more than 1 mm. “About a millimeter” is only a rough comparison.

Is a dime three-quarters of an inch across?

No. Three-quarters of an inch is 19.05 mm. A dime is 17.91 mm across, about 1.14 mm narrower.

How many dimes make one centimeter in thickness?

Dividing 10 mm by 1.35 mm gives about 7.41 nominal thicknesses. Seven total 9.45 mm and eight total 10.8 mm. Neither is exactly one centimeter.

Can I measure accurately with a dime?

It is useful as a familiar visual reference. For a precise measurement, use a ruler, caliper or another suitable measuring instrument and check the actual object.