US Coin Specifications Table
| Coin | Diameter (mm) | Weight (g) | Thickness (mm) |
|---|---|---|---|
| Penny 1¢ | 19.05 | 2.500 | 1.52 |
| Nickel 5¢ | 21.21 | 5.000 | 1.95 |
| Dime 10¢ | 17.91 | 2.268 | 1.35 |
| Quarter 25¢ | 24.26 | 5.670 | 1.75 |
| Half dollar 50¢ | 30.61 | 11.340 | 2.15 |
| Golden dollar $1 | 26.49 | 8.100 | 2.00 |
Every current US coin has its weight, diameter and thickness fixed in federal law - 31 U.S.C. 5112 spells out exactly what a quarter must weigh (5.670 grams) and measure (24.26 millimeters), and the mint strikes to those numbers. That legal precision makes coins a surprisingly good calibration set: a kitchen scale that reads a nickel as 5.0 grams is honest, and a pile of one denomination can be priced by weight alone.
Weighing coins is the original counting machine. Because dimes and quarters were sized in the silver era so that a pound of either is worth twenty dollars, banks and vending operators still price sorted coin by weight, and the converter below does the same: pick a denomination, enter the weight from your scale, and read the count, face value and leftover grams.
How to use
- Pick the denomination, type the total weight in grams from your scale - count, face value and leftover grams appear instantly.
- Type 453.6 to see the classic '$20 a pound' result: 200 dimes or 80 quarters, both twenty dollars - a dollar of either weighs exactly 22.68 grams.
- For mixed jars the denomination that matches your sorter matters - weigh after sorting, not before, or the blend averages lie.
Frequently asked questions
How much does a quarter weigh?
5.670 grams, 24.26 millimeters across, 1.75 millimeters thick - copper-nickel clad over a copper core, per 31 U.S.C. 5112. Quarters dated 1964 or earlier are 90 percent silver and weigh 6.25 grams, which is why pre-1965 silver coins vanish from circulation: the metal is worth more than the face.
Why does a dime weigh less than a nickel?
Because denomination tracks silver content from the 19th century, not size: a dime (2.268 g) is smaller and lighter than a nickel (5.000 g) even though it is worth twice as much. The five-cent coin was named for its metal - 25 percent nickel plating over copper - while dime and quarter weights were set so their silver content stayed proportional to face value.
Why are dimes and quarters both worth $20 per pound?
Because a dollar of dimes weighs exactly a dollar of quarters: ten dimes are 10 x 2.268 = 22.68 grams and four quarters are 4 x 5.67 = 22.68 grams, a silver-era design that fixed face value to mass. Scale it up and 453.6 grams - within a gram of a US pound - is 200 dimes or 80 quarters, both twenty dollars, which is why banks still buy sorted coin by weight. The clad coins kept the silver-era weights, so the design survives at any coin counter.
When did the penny stop being copper?
Mid-1982, when the mint switched from bronze (3.11 grams, mostly copper) to copper-plated zinc (2.500 grams) because the metal in a penny was about to pass its face value. Weigh the two on a gram scale and the year divides cleanly - 3.11 means bronze-era, 2.50 means zinc, and a few 1982 issues exist in both.
Which US coin is the biggest?
The half dollar: 30.61 millimeters across and 11.340 grams, the heaviest and thickest circulating coin at 2.15 millimeters. The golden dollar is a touch wider than a quarter (26.49 mm) but far lighter at 8.100 grams - manganese-brass over a copper core.