The dime is the smallest U.S. coin in circulation, at 17.91 mm wide. The cent is bigger than the dime, at 19.05 mm wide.
That surprises most people the first time they sort a coin jar: the 10-cent piece is smaller than the 1-cent piece. U.S. coin sizes were set by metal content in the silver era, not by denomination, and the modern clad coins kept the old silver dimensions. This chart gives the exact diameter and weight of every current U.S. coin, plus the classic silver coins stackers handle every day.
U.S. Coin Sizes: Current Coins by Diameter
| Coin | Diameter | Weight | Composition note |
|---|---|---|---|
| Dime (Roosevelt) | 17.91 mm (0.705 in) | 2.268 g | Smallest current U.S. coin |
| Cent (Lincoln) | 19.05 mm (0.750 in) | 2.5 g (3.11 g copper, pre-1982) | Bigger than the dime |
| Nickel (Jefferson) | 21.21 mm (0.835 in) | 5.000 g | Thickest-feeling small coin |
| Quarter (Washington) | 24.26 mm (0.955 in) | 5.670 g | Same size as the silver quarters before 1965 |
| Half dollar (Kennedy) | 30.61 mm (1.205 in) | 11.340 g | Largest circulating denomination coin |
| Dollar coin (Sacagawea / Presidential) | 26.49 mm (1.043 in) | 8.100 g | Golden color, manganese brass |
Classic Silver Coin Sizes and Melt Values
The pre-1965 silver coins share sizes with their modern clad replacements — a Mercury dime is exactly the size of a Roosevelt dime — because the Mint changed the metal in 1965, not the dimensions. What changed is the silver inside, and that is where the money is:
| Silver coin | Diameter | Silver content | Melt value |
|---|---|---|---|
| Silver dime (Barber, Mercury, Roosevelt) | 17.91 mm | 0.0723 troy oz | $3.81 |
| Silver quarter (Barber, Standing Liberty, Washington) | 24.26 mm | 0.1808 troy oz | $9.54 |
| Silver half dollar (Barber, Walking Liberty, Franklin, Kennedy 90%) | 30.61 mm | 0.3617 troy oz | $19.08 |
| Silver dollar (Morgan, Peace) | 38.10 mm (1.500 in) | 0.7734 troy oz | $40.79 |
Melt values from Data by Bullion Price Check, data as of November 9, 2026 (silver spot $52.74 per troy ounce). Melt is metal value only, before any premium; dealer prices sit above melt and exclude shipping and tax.
Bullion Coin Sizes: Silver Eagle and Gold Eagle
Modern bullion coins are sized to their metal weight, not to the old circulating planchets. The American Silver Eagle is 40.6 mm wide and weighs 31.1035 grams — exactly one troy ounce of .999 fine silver (see how many grams are in a troy ounce). The 1 oz American Gold Eagle is 32.7 mm wide and weighs 33.93 grams in total, because its 22-karat alloy adds copper and silver on top of the full troy ounce of gold it contains. Fractional Gold Eagles step down at 27 mm (1/2 oz), 22 mm (1/4 oz) and 16.5 mm (1/10 oz).
Why Coin Size Matters: Rolls, Tubes and Capsules
Size is practical, not trivia. Coin tubes, albums and air-tite capsules are all sold by millimeter diameter, and a 40.6 mm Silver Eagle capsule will not fit a 38.1 mm Morgan dollar properly. Roll counts also follow the old sizes — a standard roll holds 50 dimes, 40 nickels, 40 quarters, 20 half dollars or 20 small dollars, which is why our guide to how many coins are in a roll pairs counts with diameters. When you sort an inherited jar, diameter is also the fastest first sort: anything 17.9 mm and dated before 1965 is a silver dime, whatever its design.
Shop Coins by Size
The biggest coin on this page is the one most stackers actually buy: the 2026 Silver American Eagle – BU at 40.6 mm and a full troy ounce of silver. At the classic end, $1 Face Value 90% Silver Mercury Dimes – XF give you the 17.91 mm silver dime in bulk, and the 1 oz Gold Eagle – BU is the 32.7 mm gold standard. For the dime’s own story, read our Mercury dime value guide.
Coin Weights by Coin: The Classic Denominations
Diameter is only half the lookup — weight is the other half, and it is the number that authenticates. These are the as-struck weights of the classic U.S. gold denominations and the standard silver coins, with the fine metal each one holds:
| Coin | Weight | Fine content |
|---|---|---|
| $1 gold piece (1849–1889) | 1.672 g | 0.0484 ozt gold |
| $2.50 Quarter Eagle | 4.18 g | 0.1210 ozt gold |
| $5 Half Eagle | 8.36 g | 0.2419 ozt gold |
| $10 Eagle | 16.72 g | 0.4838 ozt gold |
| $20 Double Eagle | 33.44 g | 0.9675 ozt gold |
| Silver dollar (Morgan / Peace) | 26.73 g | 0.7734 ozt silver |
| Half dollar (90% silver) | 12.50 g | 0.3617 ozt silver |
| Quarter (90% silver) | 6.25 g | 0.1808 ozt silver |
| Dime (90% silver) | 2.50 g | 0.0723 ozt silver |
| War nickel (35% silver) | 5.00 g | 0.0563 ozt silver |
Coin Silver: What Purity Actually Means
“Coin silver” is a specification, not a compliment: from 1837 to 1964, U.S. silver coinage was .900 fine — 90% silver, 10% copper for hardness. Sterling silver is .925 fine, the British standard until 1919 and the jewelry standard today; modern bullion coins are .999 fine or finer. When a listing describes a coin as coin silver, it is claiming that 90% standard — the number behind every melt calculation on this site. Our sterling silver vs pure silver guide untangles the terms dealers mix together.
Frequently Asked Questions
What is the smallest U.S. coin?
The dime is the smallest U.S. coin in circulation. It measures 17.91 mm (0.705 inches) in diameter and weighs 2.268 grams — smaller than the cent, which is 19.05 mm wide.
Why is a dime smaller than a penny?
Because dimes were originally silver and cents were copper. A silver dime in 1796 held one-tenth the silver of a dollar, which made it physically tiny, while the copper cent’s size was set by copper’s much lower value per gram. The proportions stuck when both coins later changed metal.
How big is a Silver Eagle?
An American Silver Eagle is 40.6 mm in diameter and 2.98 mm thick. It weighs 31.1035 grams — exactly one troy ounce of .999 fine silver — which makes it larger than a Morgan or Peace dollar (38.1 mm).
What size capsule fits a Morgan dollar?
A Morgan dollar needs a 38.1 mm capsule. Silver Eagles (40.6 mm) and classic silver dollars (38.1 mm) take different capsules, so check the millimeter size before ordering tubes or air-tites.
Are silver dimes the same size as clad dimes?
Yes. Barber, Mercury and silver Roosevelt dimes are all 17.91 mm, exactly the size of today’s clad dime — the Mint changed the metal in 1965, not the dimensions. Weight gives them away instead: a silver dime weighs 2.5 grams against 2.268 grams for clad.
Educational content only — not financial advice.