Medieval Weights and Measures

The following systems arose from earlier systems, and in many cases utilize parts of much older systems. For the most part they were used to varying degree's in the medieval age's and surrounding time periods. Many parts of the system found there way into some later systems, such as many of the English units and even some S.I accepted units.

English System

English

• barleycorn – Basic Anglo Saxon unit, the length of a corn of barley. The unit survived after 1066, but now defined as 1/3 inch. Note the relation to the grain unit of weight.
• digit – 3 / 4 inch
• ynch – Anglo Saxon inch, 3 barleycorns. Based on the uncia from 1066.
• nail – 3 digits
• palm - 3 inches
• hand – 4 inches
• shaftment - Width of the hand and outstretched thumb, 6 1/2 ynches before 1066, 6 inches thereafter
• span – Width of the outstretched hand, from the tip of the thumb to the tip of the little finger, 3 palms
• foot – Usually 13 ynches but also other variants. Shortened by basing it on the Roman pes from 1066.
• cubit – Forearm, 18 inches
• ell – Elbow, 20 nails or 45 inches. Mostly for measuring clothing
• yard – Introduced after 1066, 3 feet.
• fathom – From one fingertip to the other, 6 feet
• furlong – "Furrow long" (Saxon furrow is fuhr), based on the stadion, defined as 40 rods
• league – Usually three miles. Intended to be an hour's walk.
• mile – Introduced after 1066, originally the Roman mile at 5000 feet, in 1592 it was extended to 5280 feet to make it an even number of furlongs.
• rod – Saxon gyrd measuring stick, might have been from 20 "natural feet". Retained its length but redefined as 16 1/2 Roman feet after 1066.
• chain – Gunter's Chain, introduced in the 17th century, 66 foot alternative to the rod for land measurement.

Area

• acre – Saxon unit, meaning "field", one furlong by 4 rods. Probably meant to be "as much area as could be plowed in one day".

Weight

• 1 ton = 2240 lb exactly. (This amount is called a long ton in US customary units)
• 1 hundredweight = 112 lb exactly. (This amount is called a long hundredweight in US customary units )
• 1 ounce (oz) = 16 dr exactly = 437.5 gr exactly = 0.028 349 523 125 kg exactly
• 1 pound (lb) = 16 oz exactly = 7000 gr exactly = 0.453 592 37 kg exactly
• 1 grain (gr) = 64.79891 mg exactly
• 1 dram (dr) = 27.34375 gr exactly
• 1 scruple (s ap) = 20 gr exactly
• 1 pennyweight (dwt) = 24 gr exactly
• 1 dram apothecaries (dr ap) = 3 s ap exactly
• 1 ounce apothecaries (oz ap) or ounce troy (oz t) = 8 dr ap exactly = 480 gr exactly
• 1 pound apothecaries (lb ap) or pound troy (lb t)= 5760 gr

Miscellaneous

• score – 20

Later Use

Much of the units would go on to be used in later Imperial units and in the US system, which is based on the English system from the 1700s.