digit

ancient Roman unit of measurement

Also known as: digitus

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Last updated

July 15, 2026

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The Roman unit of measurement known as the digit (digitus) was derived from the Roman foot (pes). The Roman foot was approximately 11.64 English inches (296 mm). The digit was equal to 1/16 of a Roman foot, making it about 0.73 inches (18.5 mm). This unit was one of the basic linear measures used in ancient Rome, alongside others like the inch (uncia) and the palm (palmus). The digit's origin can be traced back to early systems of measurement that often used body parts or common natural items as standards.12

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measurement system
Greeks and Romans
…terms of these equivalents, the digit (digitus), or 1/16 Roman foot, was 18.5 mm (0.73 inch); the inch (uncia or pollicus), or 1/12 Roman foot, was 24.67 mm (0.97 inch); and the palm (palmus), or 1/4 Roman foot, was 74 mm (2.91 inches).
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…terms of these equivalents, the digit (digitus), or 1/16 Roman foot, was 18.5 mm (0.73 inch); the inch (uncia or pollicus), or 1/12 Roman foot, was 24.67 mm (0.97 inch); and the palm (palmus), or 1/4 Roman foot, was 74 mm (2.91 inches).
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