Cubit (cbt)

Medieval EnglishHistorical unit (no longer in standard use)Approximate value

Traditionally the length from the elbow to the tip of the middle finger. The common English cubit is taken as 18 inches (45.72 cm); ancient cubits ranged from about 44 to 53 cm.

1 cubit = 0.4572 meters (approximately).

Approximate value. Standards for the cubit varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About the cubit

From the Latin cubitum, meaning elbow, the cubit was the forearm measured from the elbow to the fingertips. English use tied it to roughly 18 inches, or 45.72 cm. Such a hand-and-arm measure is the same idea that produced the ell, which Wikipedia describes as originally a cubit.

No single value ever governed it. Wikipedia lists most ancient cubits between 44.4 and 52.92 cm, from the Roman cubitus of about 444 mm, which Vitruvius set at one and a half Roman feet, to the Egyptian royal cubit near 523 to 529 mm. Medieval Islamic cubits ranged far wider still.

The English ell eventually settled at 45 inches, one and a quarter yards, while the cubit faded from commerce. A trace survives in hedgelaying, where a forearm of about 18 inches sets the spacing of stakes. The figure used here is the 18 inch English cubit.

Sources: Wikipedia: Cubit; Wikipedia: Ell

Cubit conversion chart

1 cubit expressed in every other length unit:

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