1 Cubit = 1 forearm
1 Cubit = 1 forearm

Have you ever wondered how exactly to convert those pesky biblical “cubits” into modern feet or metres? Now you can with the Cubits Converter and Ark Size Calculator!

The basic problem with converting cubits to modern feet or metres is that you can’t do it exactly, because the cubit is a rough measurement, referring to the length of a man’s forearm (from elbow to fingertips). An average man’s forearm in antiquity is possibly about one-and-a-half feet, although we can’t really be sure, and on top of that, you can find a variety of different types of ancient cubits, such as the royal cubit, which tended to be a little bigger. Standardization of the cubit was a late, post-Old Testament development.

But the Cubits Converter provides conversions from a whole range of different measurements for the cubit: the Current World Almanac cubit, Roman cubit, Ancient Isra[e]li [sic] cubit, Egyptian cubit, Hezekiah’s cubit, Hebrew cubit, Greek cubit, Noah’s cubit, Ancient Egyptian cubit, Royal Egyptian cubit, Hebrew long cubit, Arabian black cubit, Assyrian cubit, Biblical cubit, Royal Babylonian cubit, Holy cubit, and Arabian Hasimi cubit. Unfortunately, however, despite the great selection and imaginative names for these cubits, what the converter doesn’t provide is a definition of any of them. What’s more, some of these, such as the “Isra[e]li cubits”, “Holy cubits”, and “Noah’s cubits” sound more than a bit suspect.

Despite all these problems, if you’re measuring Giant heights, you’d be fairly safe to use the ones which have an “inches equivalent” of just under 18 inches.

So, for example, using “Hezekiah’s cubits” (1 cubit = 17.75 inches), we get the following conversions:

Goliath (LXX Deut. 17.4): 4-and-a-half cubits tall – 6.66 feet – 2.03 metres
Goliath (MT Deut. 17.4): 6-and-a-half cubits tall – 9.61 feet – 2.93 metres
King Og’s Sarcophagus (Deut. 3.11): 9 cubits long – 13.31 feet – 4.06 metres

More on the height of Goliath here.