The medieval Nordic systems of weights and measures varied considerably over space and time, and with respect to the object(s) being measured. One must distinguish between
A) measures of capacity and volume (‘rummål’),
B) measures of 1) length and 2) surface/area (‘jordmål’) and
C) measures of weight.
Some terms occurred in more than one category, for example tunna and fjärding, which might denote volume as well as area or length, depending on context. The units were generally parts of larger, hierarchically structured terminological systems. As examples of such connections, some terms have been included that are not found in the provincial laws (e.g. tunna, skippund and skálpund). On the other hand, it is virtually impossible, for reasons of space, to accommodate all local variations in a general survey. For this reason, only the more important regional differences are considered.
OSw measures of grain were sal(d)/soldh (145.8 litres in WSweden), usually divided into 6 skæppor, each containing c. 24.6 litres. Of the same size as the soldh was the tunna. Much used was the unit spander (ODan spand, ON spann) (c. 73 litres), divided into fiærþungar (‘fourths’) of 18.3 litres.
In Denmark the main unit was tunna (ODan tønde), varying in size from 139 to 194 litres. Spand was 1/8 tønde, i.e. c. 17 litres as a measure of oats; usually spand was a measure of butter (1/16 tønde, i.e. 8.7 litres).
In Norway and Iceland the sáld was the largest unit (in Iceland also a measure of liquids), varying in size between 97.2 and 132.4 litres, divided into 6 mælar of 22 litres (Iceland) or 16.2 litres (Norway). The sáld could also be divided into 4 skeppur of 24.3 (SNorway) or 32.4 litres (NNorway). Alternatively, in ENorway (including Bohuslän) the sáld was divided into 12 séttungar (OSw siattungar, known from Norrland); in Magnus lagabætrs landslög, ‘King Magnus the Law-Mender’s Law of the Realm’ (1274) 1 séttungr equalled 1/4 mælir, varying in size between 5. 4 and 12.1 litres. Towards the end of the Middle Ages, the sáld was replaced by the tunna, varying in size between 97 and 145 litres, in WNorway even 162 litres. The tunna was usually divided into 4 mælar or 6 spæn (pl. of spander); in WSweden 6 skæppor of 24.8 litres; in DL 1/6 tunna was called a trö.
As a measure of butter, spander and tunna were used in all the Nordic countries. The spann varied in Norway from c. 4 to c. 16 litres. The Icelandic skjóla (= spann) contained c. 4 litres.
A third frequent unit was the (OSw) löper (ODan løp, ON laupr), varying in size between 10 and 21 litres (i.e. from 2 up to 4 steelyard pounds, ‘bismerpund’, or from 48 to 96 merkr); in WSweden 1/9 tunna, in Denmark usually 1/6 tønde, in Gotland 1/4 tunna.
As far as shiploads and cargo of salted goods, e.g. fish (but also grain), are concerned, the largest unit was the læst (ON lest) (c. 1,600−2,000 kg), divided into 10 or 12 skippund of 170 kg (in Denmark 126 kg, in ENorway 185, in WNorway 148 kg); 1 skippund equalled 24 li(f)spund (lispound) of 8 kg (Sweden and Denmark) or 9 kg (Norway). The li(f)spund was divided into 16 skålpund of 415 g (Sweden) or 496 g (Denmark) or 428 g (Norway).
An important ON grain measure was the vétt/vætt, ranging from 6 to 46 kg. In weighing fish the vág (18 kg) was a unit in WNorway.
