Farm-derived units of measurement:
- The rod is a historical unit of length equal to 5½ yards. It may have originated from the typical length of a medieval ox-goad.
- The furlong (meaning furrow length) was the distance a team of oxen could plough without resting. This was standardised to be exactly 40 rods.
- An acre was the amount of land tillable by one man behind one ox in one day. Traditional acres were long and narrow due to the difficulty in turning the plough.
- An oxgang was the amount of land tillable by one ox in a ploughing season. This could vary from village to village, but was typically around 15 acres.
- A virgate was the amount of land tillable by two oxen in a ploughing season (30 acres).
- A carucate was the amount of land tillable by a team of eight oxen in a ploughing season. This was equal to 8 oxgangs or 4 virgates.
How big is an acre?
One acre is about 4046 square meter or 43560 square feet or 0.4 of a Hectare.