When many of us hear the word ‘rod’, we automatically think of a fishing rod. But did you know that a rod is actually a unit of measurement?
Rods are units of measurement used by surveyors to measure various different lengths from whole numbers to acres of square measures. However, there is also a standard length associated with the average fishing rod, so it’s useful to be aware of both measurements.
Today, we’re going to be explaining the rod (as a unit of length, area and volume) in depth as well as the length of the fishing rod.
By the end of this article, you will have a good idea of the different lengths associated with the ‘rod’, and how to differentiate between the two. We’ll start by defining the rod as a unit of measurement before moving onto the fishing rod.
How Long Is A Rod (Unit Of Measurement)?
If you ever hear a surveyor talking about ‘rods’, the chances are that they’re talking about the unit of measurement as opposed to the tool used for fishing.
A rod, in customary modern US units, is defined as a length measuring 1.5 survey feet (US). This is equal to 5.03 meters or 1/4 of a surveyor’s chain. In the context of surveyor’s miles, the equivalent is 1/320.
If you’re not familiar with surveyor’s units, it might be more helpful for you to think of a rod in terms of 16.5 feet, which is equal to 5.03 meters.
The thing that makes the rod unique as a unit of measurement is its whole number multiples. This enables a rod to make an acre of square measure, which is useful for farmers who want to measure their lands in units of 10 rounds.
Since the perfect acre is equal to 40 rods plus 4 rods, meaning it’s also equal to 160 square rods. Alternatively, you could think of this as 10 square chains.
Admittedly, the rod is no longer used as a common unit of measurement, but it is still used in specific situations because it can be so useful.
For example, although surveyors don’t use the rod very often, it’s still used for dividing farming lots, taking measurements in the context of real estate, measuring areas for legal purposes, pipeline easement acquisition measurements, and measuring factors in canoe portages (see also our article on canoe dollies).
The Reason Behind The Length Of A Rod
You might be wondering why a rod measures the length that it does, although many of us don’t often think about why units of measurement line up the way they do.
The reason the rod measures 16.5 feet is simply because of convenience. Since it’s easiest for farmers to finish and measure land using a 10-inch plowshare, and a plowshare is roughly 16.5 feet in length, making the rod 16.5 feet long made perfect sense.
A Brief History Of The Rod
As we just mentioned, most of us typically accept the units of measurement we’re familiar with as facts without inquiring too much into the history of these measurements.
However, the rod happens to have quite an interesting history, which we’re going to delve into now.
The 15th And 16th Centuries
The earliest recorded use of the rod as a measurement dates back to the 15th century, when the main unit of measurement used to measure length was the perch.
The perch was used to record lengths measuring 18 feet, 20 feet, 22 feet, and 24 feet. These measurements translate to 5.49, 6.1, 6.71, and 7.32 in meters.
However, moving into the 16th century, land surveyors began using chains measuring 66 feet and rods of perch-length to record these measurements.
The real turning point came in 1536, when King Henry VIII of England took over the land belonging to the Roman Catholic Church and sold it to fund his armies.
During this process, the surveyors divided the land up into squares, and this was done using the chain and rod system described above. At this point, the acre became widely defined as measuring 10 square chains.
The 17th Century (Edmund Gunter)
Another development in the rod measurement system came in the 17th century (1607, to be precise) when English mathematician Edmund Gunter established the rod as a standard survey measure.
This was when the rod was equated to 1/4 of a 66-foot chain, which comes to 16.5 feet.
This development ensured that the rod could be used to measure what is known as a perfect acre, meaning an acre that measures exactly 43,560 feet squared, or 4046.8564 meters squared.
The sides of the perfect acre should measure 660 feet in length, or 201.168 meters, which is equal to a furlong, and 66 feet or just over 20 meters in width. This can be more easily measured using lengths and widths of 40 and 4 rods.
The 20th Century
In 1965, the rod was phased out legally as a unit of measurement in the United Kingdom due to the introduction of the metric system.
However, this does not mean that the rod is never used today.
As we mentioned earlier, there are certain measurement tasks, such as measuring canoe portages and real estate or farming measurements, where the use of the rod is still appropriate because it greatly simplifies the task.
It is still occasionally used in legal contexts and is the most common unit of measurement in pipeline easement acquisitions.
How The Rod Compares To Other Units Of Length
We have already touched on the ways in which the rod relates to meters and feet, but it is helpful to have a direct guide to how the rod compares to other units of length if you’re trying to conceptualize this measurement for the first time.
Here is a breakdown of how the rod translates in terms of other units of length:
- 16.5 feet
- 1.3310748220099 rood
- 0.0050292 kilometers
- 0.003125 miles
- 5.0292 meters
- 5.5 yards
- 502.92 centimeters
- 5029.2 millimeters
- 198 inches
In addition to this, it’s important to remember that 160 square rods are equal to 1 acre.
There are also equivalents, or near-equivalents to the rod used in other countries, such as:
- Pertica (used in Venice)
- Ruthe (used in Sweden and Germany)
- Canna (used in Spain, Morocco, Italy and Sicily)
How Many Perches Per Rod?
A perch is often used as an interchangeable term for either rod or pole in some countries. However, there is actually a subtle difference between the length of a rod and the length of a perch.
One perch is equivalent to a length of 5.5 yards, which means that a rod equals 0.86 perches, not one perch.
How The Rod Measures Area
We already know that a rod can be used to measure both length and area, but since the rod is now used to measure area (such as farm land) more often than it is used to measure simple lengths, we thought it would be a good idea to dedicate a section to the rod as a measurement of area.
In order to use the rod to measure area, you need to use square measurements. A square rod is equal to 16.5 square feet or 30.25 square yards, meaning that a single acre is equal to 40 rods multiplied by 4 rods.
Measuring Volume Using The Perch
This is where things can get a little confusing because the unit of volume typically used in the context of masonry is the perch, and as we have already discussed, a perch is sometimes considered to be exactly equal to a rod although a rod is actually slightly smaller (0.86 of a perch).
However, in masonry, the perch is considered to have the same length as a rod (16.5 feet) with a height of 45.7 centimeters and a width of 12 inches.
The Rod Vs. The Furlong
If you’re wondering what the difference is between a rod and a furlong, the answer is that there is actually quite a significant difference!
While a rod measures 16.5 feet, a furlong is 660 feet long. Alternatively, you might look at it this way: a rod measures 5.5 yards, and a furlong is 220 yards.
When you do the math, that means that a single furlong is the equivalent of 40 rods. If you recall what we said earlier about an acre measuring 40 by 4 rods (160 square rods), this then means that an acre is equal to a furlong multiplied by 4 rods
To break that calculation down further, a rod is equal to 0.025 of a furlong.
What Is A 10-Rod Allotment?
A 10-rod allotment is a term used to describe an area measuring 10 square rods, which is equal to 253 meters squared.
Measurements like these can be difficult to conceptualize when you’re working with the figures alone, so to put that into perspective, a 10-rod allotment is roughly the same size as a doubles tennis court, which measures 78 feet in length and 36 feet across.
So, why is the 10-rod allotment a popular enough land area to warrant its own terminology? Well, it all comes down to farming practices again.
A 10-rod allotment (253 square meters) is pretty much the perfect size for perennial crop cultivation as well as specific livestock rearing.
While a 10-rod allotment is obviously significantly smaller than an acre based on the calculations we’ve outlined above (an acre is just under 4047 square meters or 160 square rods), the 10-rod allotment is an ideal land measurement to work with when dividing full acres between different people.
While this system isn’t used much anymore, it was a popular method of land division throughout history.
What Is An 80-Rod Length?
An 80-rod length is not to be confused with a 10-rod allotment. A 10-rod allotment works in square rods and is a measurement of area, while an 80-rod length is used to measure exactly that: length.
A length measurement of 80 rods is the equivalent of 1,320 feet based on the premise that a rod equals 16.5 feet. 16.5 x 80 = 1320.
The Fishing Rod: History And Length
Now that we have discussed the unit of measurement that is the rod from various perspectives, let’s turn our attention to the other kind of rod most of us are more familiar with: the fishing rod.
The fishing rod has been developed and redesigned throughout history, evolving from its original design as a basic pole with some form of bait to the more complex rod most of us have seen at some point.
First, the running rings were added to the rod for cast line control, and then jointed rods became commonplace before finally evolving into rods with spinning reels (see also ‘Open-Face Reel: Everything You Need To Know‘) to stop the lines from getting twisted and make it easier to reel the lines back in.
In the past, fishing rods were made from different kinds of wood such as hickory, bamboo, and ash. You can still buy traditional rods today if you prefer, but these days, fiberglass and carbon fiber rods are the standard because of their increased durability.
You can get fishing rods (see also ‘Everything You Need To Know About A Walmart Fishing License‘) in different lengths depending on whether you prefer to fish in saltwater or freshwater and on the size of your intended catch.
The smallest rod you can get in most cases is about 2 feet long, although fishing rods can be as long as 50 feet.
To choose the ideal length of your fishing rod, you should first determine what kind of fish you’re aiming to catch and where you will be fishing. Your lure weight, rod speed, and line weight are also relevant factors in this decision, as well as the total pieces.
Types Of Fishing Rods
Here are the different kinds of fishing rods you’ll need to choose between if you want to buy a fishing rod:
- Fly rod (designed for casting artificial flies, measuring between 8 and 9 feet)
- Baitcasting/spinning rod (for casting baits or lures, measuring between 6 feet, 6 inches for trout or panfish and 7 feet for steelhead, bass or salmon)
- Ice fishing rod (for fishing through holes in ice, measuring between 28 and 38 inches)
- Trolling rod (for fishing from the back of a boat, measuring anywhere between 5.5 and 10 feet)
Final Thoughts
A rod is not only a tool used for fishing. It’s also an old unit of measurement equal to 16.5 feet or 5.03 meters, typically used for measuring farm land, real estate, or conducting land surveys.
The rod has mostly been phased out now, but it is still sometimes used to measure real estate, canoe portages, and to carry out legal proceedings.
