The standard dry measure for grain, and the anchor the other dry measures are fractions of.
Volume (dry)
20–24 L (5.28–6.34 gal).
Reckoned from reconstructed storage-jar capacities from Iron Age Judah.
The weakest of the three anchors. A smaller ephah of about 10 L is argued for some periods.
An ephah is the working measure of grain — what you bring for an offering, what you carry home from a field. Ezekiel ties it to the liquid bath: the two are the same volume, both a tenth of a homer, and he says so in the same breath as demanding honest scales. Its size is the least certain of the three measures this page anchors on, because it rests on reconstructed jar capacities rather than on anything inscribed.
Each basket holds its measure at the middle of the range above. The ephah is the anchor: a seah is a third of it, an omer a tenth and a cab an eighteenth, and ten ephahs make a homer, the word for a donkey’s load. An omer of manna, a day’s food for one person (Exodus 16:16), is about a 2-litre bottle’s worth.
Disputed. Estimates range from about 20 to 24 litres, and some scholars argue for a smaller ephah of around 10 litres in earlier periods.