Anglo-Saxon Weights and Measures

I can’t claim that this is a definitive document on Anglo-Saxon weights and measures. Instead, it represents my current understanding of a subject which I have found difficult to research.
I present it here in more-or-less the form it had in 2001, when it formed part of my research for a book (as yet unpublished) on Anglo-Saxon food and drink. Modern non-metric measurements are based on the British Imperial system, which is similar to the US system but uses a pound of 16 ounces and a pint of 20 fluid ounces .

24 (or 21) grains    =    1 penig    1.56g (or 1.36g)
20 penigas    =    1 yntsa    30g or 1oz
12 yntsan    =    1 pund    375g (325g) or ¾lb
15 pundas    =    1 sester    5.5kg (5kg) or 12¼lb (10¾lb)
256 pundas    =    1 amber    95kg (85kg) or 210lb (185lb)
2 ambra    =    1 mitta, or a great sester

There must have been two systems of weights, one heavy and one light, using the same terminology, so that as well as a 256-pund amber, there is a seven-and-a-half-pund amber to match the 15-pund sester, and then there is a 34-pund pund too.
The basic measure of weight in England, from ancient times until the twentieth century, was the grain of barley. The Anglo-Saxons may have used the Roman pound of 5050 grains and the Troy pound of 5760 grains. An Imperial pound is 7000 grains. Grain was used to measure length too; three barleycorns made up one inch.
A lead weight now in the British Museum bears the stamp of a King Alfred penny dated to about the year 880. This shows that it has been approved as an official measure by the king’s moneyer. At 2515 grains, it weighs just under half of one Roman pound. Coins from this period weigh in around the 21-grain mark, so the lead weight is indeed the equivalent of 120 pennies. Allowing for loss of metal from the weight, this could suggest a hypothetical Wessex pound of 5040 grains (325g or 11½oz.), made up of 240 pennies of 21 grains.
The Penig (pennyweight) was the weight of one silver penny, the standard coinage of King Alfred’s day. Around 886, Alfred raised the weight of the penny from about 21 grains (1.36g), to about 24 grains (1.56g) in line with Troy weight.
The Ashmolean Museum in Oxford has 39 undamaged Alfred pennies. Of these, 14 coins come within a grain of 21 grains, and 19 coins are within a grain of 24 grains. Another two are within 1.1 grains of 24 grains, giving a total of 35 coins or 90%, which approximate to one of the two supposed standards. Perhaps, not all of these coins may have been intended to comply with the standard which they are closest to, but the two clusters around 21 grains and 24 grains are statistically significant.
The Yntsa (ounce or fluid ounce) was made up of twenty penigas.
The Pund (pint or pound) was twelve yntsan, or two hundred and forty penigas.
The Troy pound (5760 grains) which Alfred seems to have adopted, is roughly 375g or 13oz; an old Wessex pound probably weighed about 325g or 11½oz. By this estimation a Wessex pound is precisely 18 twenty-fifths of an Imperial pound; the Wessex ounce is 24 twenty-fifths of an Imperial ounce.
A pund of water was a pund by weight (pound) as well as a pund by volume (pint).
There was another measure also called pund, which must have been very much bigger, so much larger that confusion was unlikely. It probably bore the same relation to the little pound as the great sester did to the little sester, which is about thirty-four times greater. By this reckoning the "12 pounds of good corn" allowed to a male slave each year, work out at about one pund (375g or ¾lb) a day, and the "8 pounds" allowed to a female is three fourths that, or nine ynstan.
Sester – fifteen pundas, according to the Anglo-Saxon Leechbook.
As with the pund, there was a much larger measure also called sester. Henry of Huntingdon says that a sester of wheat was the burden of one horse. The burden of a horse was counted as eight London bushels. A London bushel is 64 pundas, so a great sester comes out at 512 pundas, which is about 34 times bigger than the little one.
An amber (from Latin amphora) is four bushels liquid measure, or 32 gallons, which is an Anglo-Saxon barrel. A mitta is twice that, so 64 gallons, or a hogshead. This is 512 pints, which makes it the same in pundas by volume as is estimated for the great sester in pundas by weight.
In King Alfred’s day, it was often easier to measure by volume than by weight, so measurements by volume are the commonest Anglo-Saxon measures. This means that a measure of wheat, for instance, might weigh more than the same measure of oats.
A pund of oil weighs 12 pennies less than a pund of water, & a pund of ale weighs 6 pennies more than a pund of water, & 1 pund wine weighs 15 pennies more than 1 pund water, & a pund of honey weighs 34 pennies more than a pund of water, & 1 pund butter weighs 80 pennies less than a pund of water, & a pund of beor weighs 22 pennies less than a pund of water, & 1 pund meal weighs 115 pennies less than a pund of water, & 1 pund beans weighs 55 pennies less than a pund of water, & there are 15 pund of water to the sester.
Each town had its own measures, which might be quite different from those in the next. Clearly, this caused problems for trade. Under King Edgar, and later under King Aethelred and again under King Knut, attempts were made at standardisation, but in 1086, the Norman Domesday Book still found regional variations, which accounts for such comments as "by the measure of the town."

A cumb was probably the same as an amber, but used for dry measure; in the early twentieth century, a sack or comb of oats weighed 12 stone, barley 16 stone, and wheat 18 stone. A mitta was twice this and so equal to a quarter (or roughly four hundredweight, depending on what was being measured), but sometimes to ten bushels (or five hundredweight).
A wey of tallow was 168 pundas; 28 cloves of six pounds each.
64 pundas to the bushel. 8 bushels to the quarter. A quarter being a quarter ton.
112 pounds to the C13th hundredweight.
A vat (fæt) might hold two or three mittan (128 to 192 gallons or 18 to 27 pints). A kettle (cytele) held between three and five ambers (ambru) (96 to 160 gallons or 13½ to 22½ pints).
It is possible that where the Leechbook says, "there are 15 (xv) pund to the sester," it should read "there are 16 (xvi) pund to the sester." This would make the sester equivalent to the gallon and more compatible with other Anglo-Saxon measures. It is conceivable that the word sester is derived from the Old English word siextiene (‘sixteen’), possibly under the influence of the Latin sextarius (the Roman pint, equivalent to about 14.75 fluid ounces). However the horse-load of salt (which may have been a ‘great sester,’ see below) was divided, according to the Domesday Book, into 15 bulliones, which suggests that a sester of 15 pundas is likely to be correct.