System of Weights and Measures
A brief overview of the design and workings of both the Trade Unit and Imperial Unit systems for weight, distance, and liquid measure. (Part 2)
WORLD BUILDINGEXPLORING TREXLIN
7/10/20253 min read


In the beginning, I had some basic "measurement" units (the Beat and the Trant - time and length) but I needed more. I then set about creating a unified (or at least somewhat consistent) system of weights and measures.
I first started with the Empire of the Platinum Lion - since that is where a lot of my RPG campaigns were based - and, unsurprisingly, also the central location for most of the events in Awakening the Seablade.
In keeping with the Empire theme of how things were named, I first started on units of length. I knew that worldwide the Trant was going to be the basic length measurement - I also knew that the Empire - desiring to put their stamp on everything - would have their own system. Therefore, I decided on:
Talon - the smallest unit of length. Equiv to about 0.75"
Pad - the next higher unit - the most common 'small' unit. Equiv to approximately 3"
Paw - the next order higher. Equal to 3 Pads - or about 9"
Leg - One unit higher. Equal to four paws - or 36"
Leap - Equals 4 legs - or 12 feet.
Hunt - Equals 100 leaps or 1,200 feet
Stride - Equals 4 hunts or 4,800 feet.
Strande (depreciated unit) - originally was approximately the distance a person could walk in a chime (roughly 30 minutes). Roughly 7,765 feet.
Area is a Tract (trt) in Imperial Units and is defined as 75² Legs (about 1.16 Acre)
While the Empire made this the official measurement system and use it internally. It is known as Imperial Units (IU). In practice, many other nations - especially those that were actively involved in trade - had standardized units already. Note: The Threv developed the Standardized Units - which are known as Trade Units (TU).
The IU for liquid measure are as follows:
Spaff (spf) = equivalent to about 3.6ml
Draw (drw) = 10 Spaff (or 36ml)
Mug (mg) = 10 Draw (or 364ml)
Round (rnd) = 4 Mug (or 1.456 liters)
Lionshead (lnh) = 100 Rounds (145.6 liters)
Barrel (brl) = 125 Rounds (182 Liters)
Tank (tnk) = 15 Lionshead (2,184 Liters)
Now - it is interesting to note that the Barrel was not an original IU. However, it is a common measurement for liquid in commerce - and is included in the Trade Units. It has been adopted by the Empire for practical purposes.
It is interesting to also note that a Mug is considered a typical serving size in most taverns and has been unofficially adopted in the TU system. A barrel will yield 500 Mugs (servings) while a Lionshead yields 400 so it is a practical size for tavern owners, innkeepers and the like when calculating cost of goods.
Liquid measure in the Trade Unit system is based on the Trant. A cubic trant yields a volume which is defined as 1 Vog (Vg) - or about 1,812 Liters or 478.75 gallons.
We then have the following TU liquid measures:
Mini Vog (Mv) = 18.2 ml
Tiny Vog (Tv) = 181.2 ml
Small Vog (Sv) = 1.812 Liters
Slim Vog (Slv) = 18.12 Liters (Vog Cask)
Petite Vog (Pv) = 181.2 Liters (Barrel)
Vog (Vg) = 1,812 Liters (Vog Tank)
Grand Vog (Gv) = 18,120 Liters
While the Vog Tank is generally the largest container routinely used, there is also a Grand Vog Wagon. It is an integrated Tank/Wagon that can carry a Gv amount of liquid. Its filled weight is roughly 800 Sacks (16 Wagons) - which is about 40,000 lbs. The wagon is designed with an internal crank lift which allows draining of the liquid - as well an integrated hand pumping system. The tank dimensions for this is roughly 2 Trants diameter and 3.25 Trants length (note, this size if for the tank portion - not the entire wagon, which is slightly wider and longer.
Weights
The recognized system of weights was in place centuries before the rise of the Empire. It was used for everyday activities - and much more ingrained. So much so that implementing a completely new weight system wasn't practical.
The base unit of weight is the Kern (Kn). A Kern is defined as the average weight of a single kernel of the Yreegan grain. This is equal to approximately 0.045 grams.
Petite Kern (PKn) = 0.1 Kn (or 0.0045 grams)
Kern (Kn) = 0.045 grams
Large Kern (LKn) = 10 Kn (0.45 grams)
Grand Kern (GKn) = 100 Kn (4.5 grams)
Royal Kern (RKn) = 1,000 Kn (45 grams or about 1.59oz)
Sovereign Weight (Sw) = 500 Kn (22.5 grams or roughly 0.8 oz)
Pouch (PCH) = 20 Sw or 10,000 Kn (450 grams or 0.992 lbs)
Sack (SCK) = 50 PCH or 1,000 Sw or 500,000 Kn (22.5 Kg or 49.6 lbs)
Wagon (WG) = 50 SCK or 2500 PCH or 25,000,000 Kn (1,125 Kgs or 2500 lb)
Of note, all Imperial coins weigh exactly 500Kn - a standardized weight for all coins of the Empire.
There is another set of weights - used primarily by alchemists. These are known as Alchemist Units (Au). They include:
Drop = 1 PKn
Pinch = 7 Kn
Dollop = 21 Kn
Grasp = 49 Kn
Hand = 343 Kn
Pestel - 2,401 Kn
Bowl = 16,807 Kn
Flask = 22,222 Kn
There is a lapidary unit as well (for size of stones/gems) that falls under the TU. It is the Ray. One Ray is equal to 5 Kerns (or about 1.125 Carats).
The last system of measures is Time - which we'll deal with in a later blog post.