Throughout the Witcher series, a variety of measurements are used.
Weights
Lot
A lot is a unit of weight equivalent to half an ounce. 32 lots usually make one pound.
Ounce
An ounce is a unit of weight. Though not specifically mentioned, it seems likely that 8 ounces make one mark and 16 ounces make one pound.
Mark
A mark is a unit of weight equivalent to half a pound. Unfortunately there is no mention of how many ounces make one mark, but likely it is 8.
Pound
A pound is a unit of weight equivalent to two marks or 16 ounces.
Stone
A Stone is a unit of weight equivalent to 25 pounds.
Hundredweight
A hundredweight is a unit of weight equivalent to 100 pounds.
Quart
A quart (Polish: kwarta) is a unit of weight equivalent to 1/4 of a gallon. Typically it's used to measure liquids.
Gallon
A gallon (Polish: garniec) is a unit of weight equivalent to 4 quarts or 1/8 of a bushel. Typically it's used to measure liquids.
Bushel
A bushel (Polish: Ćwiertnia) is a unit of weight equivalent to 8 gallons and usually used for agricultural products.
Barrel
A barrel (Polish: korzec) is a unit of weight equivalent to 4 bushels.
Lengths
Inch
An inch is a unit of length equivalent of about 2.54 cm.
Span
A span is a long-standing unit of length used in the Northern Kingdoms. It is basically the average distance from the end of the thumb to the end of the little finger on an average man's open hand. That measurement is estimated differently in different places but tends to run around 9 Inches (or ~18.5 - 22.5 cm).
Foot
A foot (Polish: stopa) is a unit of length equivalent to 12 inches.
Cubit / Arszyn
A cubit is a unit of length equivalent to 18 inches. The term arszyn is occasionally used, which is the Russian cubit. It varied in length between 28– 32 inches until Peter the Great standardized it to 28 inches.
Ell
An ell is a unit of length equivalent to 2 feet (or 24 inches).
Yard
A Yard is a unit of length equivalent to 2 and a half spans or 30 inches.
Fathom
A fathom is a unit of length equivalent to 3 ells (6 feet or 72 inches).
Rod
A rod is a unit of length which is equivalent to approximately 11 cubits (198 inches).
Furlong
A furlong is a unit of length that has had various definitions over time. Vysogota of Corvo said to Ciri that the generally agreed upon reckoning is that 420 furlongs are the equivalent of about 50 miles (meaning 8.4 furlongs equals 1 mile).
Mile
A mile is a unit of length equivalent to 63,360 inches, 5,280 feet, 3,520 cubits, 320 rods, or about 8.4 furlongs.