Talk:Acre

ACRE

what is width of an acre in feet?

1 yard = 3 feet, so, 220 yd by 22 yd = 660 by 66 feet. Thus, 66 feet wide. Nik42 08:04, 11 Feb 2005 (UTC)

If your "acre" is a rectangle, then its width is 43,560 ft² divided by the length in feet. If that rectangle is a square, then each side is √(43,560 ft²), or about 208 ft 8½ in, the maximum width of a rectangular one-acre tract. Gene Nygaard 16:15, 11 Feb 2005 (UTC)

• The acre is an area measure related to stadia, perche and miles. There are 640 acres in a modern square mile. The sides are generally taken to have been made one perche by one fulong in 1593. There would be 10 such acres in a square furlong and 8 furlong in a mile.

• In 1500 Arnolds Customs of London gives the length of the furlong as 625 fote and the Myle as 5000 fote which would make it the same as the Roman Milliare. There are still 8 furlongs in a Myle Rktect 14:18, September 6, 2005 (UTC)

One perch by one furlong is a quarter of an acre. Four perches by one furlong is one acre. The pre-1593 mile was 5000 English feet, not Roman feet, so it was not the same as a Roman mile. Indefatigable 17:50, 6 September 2005 (UTC)

• First thanks for the correction.

• As to your second point,I agree that what we are talking here would be 66 fote rather than 66 pes or 60 pous although rods, poles and perch vary from about 5.5 yards or 16.5 feet to 22 feet and I was wondering if we could agree as to why. Rktect 02:48, September 7, 2005 (UTC)

Acre in Rods and Chains

One Acre is equal to 1 chain by 1 furlong. Noting that 4 rods is a chain, and 10 chain is a furlong, then one acre is also equal to 4 rods by 40 rods (160 squar rods).

After 1581 an acre is considered to be measured as 1 chain by 1 furlong. Before Gunters chain replaces whatever unit or units were there before, four perch range from 66 feet to 88 feet, afterwards his chain is what makes it 66 feet everywhere.

Most people think the perche comes to England from France, possibly at a time when it was still considered to be Normandy or Gaul. In Gaul we seem to have the pied de roi and a set of units derived from the Roman pes but east of the Rhine there was the Greek agros or amma influencing the forebearers of the Anglo Saxon units. 10 orquia = 1 amma = 1/10 stadion, stadium, furlong.

The Gauls are using Roman units and the Germanics are using a Greek unit equal to 4 perche known as the agros or amma. Agros being the Greek root of agriculture it makes sense that the agros is the unit used to lay out fields in its sphere of influence. Since the Greek foot or pous has a short median and long form and the Roman measures also have a couple of different forms that may explain why the perch varies so much throughout Europe. Rktect 02:48, September 7, 2005 (UTC)

As one chain is 22 yards, so one acre is also equal to 22 yards by 220 yards (4,840 square yards). You see, these all make sense !!! (Comments added by Dr. Eric Wu 20/03/2005)

Acre - Make it simple

Think of one acre being slightly larger than 60m by 60m.

On the topic of "simple", one should consider removing "which can be easily remembered" from the introduction. It looks ridiculous. One Ha = 100x100 is easy to remember, 43,560 being 1% less than 44,000 is not. jonatan (talk) 18:51, 19 October 2008 (UTC)

Acre's breadth

I have no quarrel with the fact that the acre was sometimes defined as a chain by a furlong, or the equivalent in perches or yards or whatever. Nor with the fact that the terminology "acre's breadth" and "acre's length" were sometimes used in connection with defining an acre.

What I object to is presenting "acre's breadth" and "acre's length" as if they are used as units of measure. That certainly isn't true today, and I doubt that it ever was true. Nobody ever gives a measurement as "three acre's breadths" or "seven acre's lengths".

BTW, the acre's breadth I learned before I even started school is the rod. In an area where homesteads were normally 160 acres, often in a square, the half-mile length of the fields in these tracts for a width of one rod is an acre. Gene Nygaard 11:13, 7 September 2005 (UTC)

"Acre's breadth" and "acre's lengths", as I stated, are obsolete terms, but formerly used. They were used as lineal measurements and date to the 13th Century. The Oxford English Dictionary contains quotes with these usages. Rt66lt 01:47, September 8, 2005 (UTC)

Are any of the usage examples used with anything other than "one" or "an"? In any case, this should be under the "History" section, not "Related measurements". Gene Nygaard 02:53, 8 September 2005 (UTC)

Where is the "history" section? Would it be possible to include the earlier versions of the acre in the same way we include the earlier versions of the mile and the foot? The romans (actus, actus guadratus, jugerum, heridia, centuria) have a number of standard multiples and divisions of the which make it into medieval usage (yerde, hide, virgate, carrucate)as do the rest of Europes nations (French arpent, German Daisework) and for that matter the Greeks, (argos, aroura, square plethron), Egyptians,(3kr, ht, 3ht, mht3, khet, sqaure st3t, itrw) and Mesopotamians, (iku) all use the same doubling system apparently based on the different stadia and chains. Rktect 20:46, September 9, 2005 (UTC)

The first usage of "chain" (as an official unit of length) dates to 1624 according to the OED. Chains were used to measure acres, however they were not standardized as a length until that date by someone named "Gunter" (no first name given).Rt66lt 02:28, September 8, 2005 (UTC)

See Edmund Gunter and Gunter's measurement. Gene Nygaard 02:53, 8 September 2005 (UTC)

The earliest argos or chain I have come across is attributed to Pythagorus at Miletus but even earlier than that we have the knotted cords used to measure land.

"In the Hellenistic era different methods were used to measure distances described for example by Heron of Alexandria. Lengths were measured by: Schoinion, a cord of some standard length, Schoinourgos, the land surveyor. Heron of Alexandria knew that for example the length of the schoinion could change by humidity and he gave some recipes how to keep the distance as constant as possible, by hanging weights or smearing the schoinion with wax. The schoinion was 100 cubits divided in 8 hammata (knots) halysis (metallic chain). This did not have the problems of the cord but it was probably expensive and too heavy to be used often as the schoinion.

kalamos measuring rod from reed or wood. For area measurements the aroura was used which is one schoinion square."

[schoinion (100 royal cubits)]Rktect 20:46, September 9, 2005 (UTC)

non english acres

It's interesting how the English and other Europeans seem to think they invented all measures from scratch but at the same time allow that by some coincidence the people who invented surveying were apparently able to lay out the metes and bounds of plots of land in essentially the same units several millenia earlier. How did the Greeks lay out their fields? Federal Street 16:14, 16 October 2005 (UTC)

Where is this claim in the article? Oh, that's right: it doesn't exist. C'mon, mon, get happy or plant yourself. — Preceding unsigned comment added by 205.232.191.16 (talk) 20:37, 3 August 2011 (UTC)

U.S. Definition of acre when listed for purchase

When buying land listed for purchase in the U.S, what is the definition of an acre?

For instance, if I search on realtor.com, and it says that a plot of land is 10.21 Acres, can I convert this to square meters?

I suspect the legal definition would be U.S. survey acre in a case like this, but I cannot say for sure. The difference between the two is only 1650 cm², which nobody would quibble over or take to court. Anyway listing something as 10.21 acres usually implies (10.21 ± 0.005) acres. By both definitions, this converts to (41,318 ± 20) m². Indefatigable 15:35, 8 December 2005 (UTC)

Generally speaking Realtors use 43,560 sq. ft. (4,046.856 square meters) to represent an acre.

Yes but the question is are those feet international feet (exactly 0.3048 m) or U.S. survey feet (exactly ¹²⁰⁰⁄₃₉₃₇ m)? Indefatigable 21:01, 9 December 2005 (UTC)

When in doubt, take your ox and see how long it takes you to plow the lot. Do the math and use it as a bargaining chip with your realtor.  ;-) Kbh3rd^talk 21:07, 9 December 2005 (UTC)

Duplication

The line

One acre equals ten square chains: ten acres equals one square furlong: an acre is a chain by a furlong: chain: 22 yards, furlong: 220 yards.

appeared in two paragraphs. I removed it from the first, thinking it more relevant in its place in the second.--King Hildebrand 17:11, 2 August 2006 (UTC)

International Acre

There is some confusion in this section, which starts by saying that the US and the Commonwealth agreed on the length of a yard, in meters. It then says there is some difference between the US and International acres, which makes no sense. The next section talks about a US survey acre. If this is the acre being referred to under International Acre, perhaps "survey acre" could be appended to "US" or the two sections could be combined to be more coherent.Cellmaker (talk) 14:47, 7 September 2011 (UTC)

error on this page

there is a comparison to an acre to a soccer. An acre is 66ft x 220 yards or 660 ft. A football field is 75 to 100 feet, by 100 yards or 300 feet. The diagram shows that the foot ball field is larger than an acre, If the football field is 100 ft by 300 feet the sq foot would be 30,000 sq ft and an acre is 66 ft by 660 feet or 43,560 feet. I think the designer mistaken the 220 yards for 220 feet, being there is 300 feet in a football field.

George Smith —The preceding unsigned comment was added by 192.76.86.83 (talk) 16:17, 23 April 2007 (UTC).

The statement that an area of 1 inch by 99 miles was incorrect so I replaced 99 with an exact calculated value.

Your "exact" caclulated value does not match my exact calculated value. It's silly anyway, and I'm going to remove it. The text says it's a measure of area that can have arbitrary dimensions. That's enough said. --Kbh3^rdtalk 03:13, 18 November 2007 (UTC)

BTW, here's my calculation using the units utility available for Unix-like environments, showing 99.000395 miles x 1 inch:

$ units
2438 units, 71 prefixes, 32 nonlinear units

You have: 1 acre
You want: in2
        * 6272665.1
        / 1.5942187e-07
You have: 6272665.1 in
You want: mi
        * 99.000396
        / 0.01010097

I.e., 1 acre is 6272665.1 square inches (in2). Take 6272665.1 1-inch square tiles and lay them end-to-end, and they'll reach 99.00396 miles. (The second number in each conversion is the reciprocal – 1 in² is 1.5942187x10^-7 acre.) I cannot personally vouch for the accuracy of that program but have no reason to suspect it. It's quite useful for calculating such things as milliliters per cubic parsec (2.9379989x10⁵⁵). But don't put any of this sort of thing into the article. It's too trivial and inconsequential to the subject of a good encyclopedia article. --Kbh3^rdtalk 16:16, 18 November 2007 (UTC)

i know that this has been resolved but 1 acre is exactly 99 miles by 1 inch. whatever program you are using is wrong and i would never use it again for anything. the math is very simple 1 acre = 43,560 square feet 1 square foot = 144 square inches 43,560*144 = 6,272,640 square inches. 1 mile = 63,360 inches. 6,272,640/63,360 = 99. i am clueless how that program converted 43,560 square feet into inches that didn't come out even, right there you should have know that your answer was going to be wrong. you shouldn't "correct" someone when you can't even do simple math yourself. — Preceding unsigned comment added by Cjamadei (talk • contribs) 22:02, 7 July 2011 (UTC)

A further comment regarding the image comparing an acre to a football field: if anyone is able, please replace the image with one that does not use red and green as the comparison colors. I am red-green colorblind (along with an estimated 7-10% of males). I am incapable of seeing the difference in color between the red area and the darker green in the image, which means that I can't see if the red area includes or does not include the left-hand endzone. Here and elsewhere, all illustrators should please use other color combinations, such as red and blue or green and yellow, that avoid this problem. Even better would be use of dark and light shades of gray, as these will be visible by anyone with eyesight, regardless of any form of color blindness they may experience. --jtellerelsberg 13 October 2009.

Another derivation of an acre

Has anyone noticed that an acre is one-tenth of a square furlong? Or is that just another wacky measurement? ZtObOr 02:21, 17 December 2007 (UTC)

It isn't wacky. An rectangle that is one furlong on the long edge (660 feet) and one chain on the short edge (66 feet) is an acre. A chain is 1/10 of a furlong. So naturally 10 such rectangles, placed with their long sides touching, would have an area of 10 acres and would form a square with each edge being one furlong long. --Gerry Ashton (talk) 02:33, 17 December 2007 (UTC)

Right. Never mind then. ZtObOr 23:04, 18 December 2007 (UTC)

Eleven

User:ArthurDuhurst added the following sentence: "Curiously, both distances, 660 ft. & 66 ft., are multiples of eleven." with the edit summary "(I added the sentence on multiples of eleven in hopes that someone will explain this oddity)". I removed the change because it belongs on the talk page, not in the article.

One of Gunter's goals was for the result of dividing a mile by the length of his new chain be an integer. The prime factorization of a mile, in feet, is 11·5·3·2⁵. The length of the chain chosen by Gunter is 66, or 11·3·2. The remaining factors of a mile are 5·2⁴, which is 80, so there are 80 chains per mile. --Gerry Ashton (talk) 14:23, 20 October 2008 (UTC)

I think the root factor is the length of the furlong at 220 yards. This is traditionally how far oxen could plough without pausing. The chain of 22 yards was a tenth of this. Why oxen should need to pause at 220 yards, not 200 or 240, escapes me, but this is related to the introduction of a new kind of plough in the Saxon period in England. Earlier fieldsystems seem to have squarer fields and suggest that the plough them in use could only be dragged about 100 yards before pausing. Peterkingiron (talk) 22:16, 20 October 2008 (UTC)

I doubt the claim that oxen had to pause after 220 yards. There is nothing to stop them from pausing and then continuing in the same line. I suspect, but have no sources to support, that the turn-around area wouldn't be much use for planting, so the 220 yards is probably a compromise between having turn-around areas at convenient intervals versus not wasting too much land that could be planted if it weren't used as a turn-around. --Jc3s5h (talk) 21:26, 13 October 2009 (UTC)

The explanation given is the standard one that is always given. Fields were usually laid out with a headland (beyond the end of the acre) for turning. This is either uncultivated or was ploughed last. The other factor in the choice of area is that it was the area that a team could plough in a day. The chain (the width of an acre) was 4 perches, but I do not know which measure came first (nor probably does any one else). Peterkingiron (talk) 21:04, 18 October 2009 (UTC)

Systemic bias

I added Template:globalize/USA because examples involving American football are really not optimal for expressing meaning to readers outside the United States. A US-centric example may be better than no example, but an internationally understandable example is better still. Obviously an acre is primarily a US/UK unit of measurement but I still anticipate that many readers will be coming from other cultures because they encounter this unfamiliar unit in sources originating in the US or UK, or historical sources. See Wikipedia:WikiProject Countering systemic bias for more. - PhilipR (talk) 18:50, 28 December 2009 (UTC)

I have modified the drawing to show an Association football field (blue tint) as well as the American one. I have removed {{globalize/USA}}. --Jc3s5h (talk) 01:42, 7 January 2010 (UTC)

Thanks, I think the dual examples are much more internationally understandable. - Regards, PhilipR (talk) 04:37, 7 January 2010 (UTC)

[which?] FAIL

the article actually says: "An acre is approximately 40% of a hectare.

One acre is 90.75 percent of a 53.33-yard-wide American football field." while the information is correct, the acusation of weasel words is not. it's not like 'some say' it is a numerical value of 1.

sort it out.

Did I mention? BLEH (talk) 20:15, 13 May 2010 (UTC)

I'm not sure what Did I mention? BLEH would like done, but I have removed the {{Which}} templates because the statements, to the stated precision, are true for any modern acre. Jc3s5h (talk) 20:37, 13 May 2010 (UTC)

Approximation?

The article states

"The United States survey acre is approximately 4,046.872 609 874 252 square metres".

In my opinion that goes well beyond what an approximation should be. The measurement is being quoted to 16 significant figures (in this case 12 decimal places) and is more akin to an exact measurement. After all, the 12th decimal place represents a square micron, which is less than the area of a pinhead, right?

An approximation ought to be no more than 3 significant figures, if that. After all, if you asked someone "Approximately how many miles can you drive this car on a full tank of petrol?" and they said "322.6345924", you'd think them rather odd. You'd expect an answer such as 300-350.

I therefore think it would be far better to state the approximation as perhaps 4,050 square metres, or something similar. —Preceding unsigned comment added by 86.163.184.82 (talk) 14:29, 28 July 2010 (UTC)

Conversion factors are, in most cases, defined by law. Any conversion factor that is not exactly equal to the legal conversion factor is approximate. However, the value stated in the article is more precise than necessary, especially considering that the exact value is also stated as a fraction. I think the approximate value could be given as 4,046.872 square metres. Jc3s5h (talk) 14:42, 28 July 2010 (UTC)

Actually, because the calculation is referenced to the Mendenhall Order it is technically correct, but it's actually wrong, since the Mendenhall Order was rendered obsolete in the Commonwealth of Nations in 1959. The new definition sets the International Yard at 0.9144 Meter (exactly). In that case the Acre is equal to 4046+(66908/78125) Sq. Meter. or 4046.856422 Sq. Meter EXACTLY. There's no "approximately" about it. The main page info should be changed to reflect the modern definition for accurate conversion.

96.255.159.197 (talk) 00:19, 25 March 2011 (UTC)mjd

It isn't that simple. If you look at NIST's "General Tables of Units of Measurement" cited in the article you will see that NIST considers the acre to consist of 43,560 square U.S. survey feet, not square international feet. The Americans who measure acres with the most precision, land surveyors, may convert from international feet, survey feet, or grid feet, depending on the situation and state regulations. (A grid foot is a foot measured in a state plane coordinate system, which projects the surface of the earth onto a plane that covers a state or a large portion of a state.)

Of course, if there are any other countries still using the acre, they will convert according to the customs or regulations of the particular country. Jc3s5h (talk) 16:38, 25 March 2011 (UTC)