Length measurements and units of measure.
These are various approximate lengths (except where noted) in comparison to my body (ca. 2004/2006), common objects, typical weapons, and such.
-
2 cm = 3/4"
-
Width of my thumb.
-
A U.S. penny is 1.905 cm == 0.750 inches in diameter.
-
2.54 cm == 1"
-
Tip to first knuckle of my middle finger.
-
A U.S. quarter is 2.426 cm = 0.955 inches in diameter.
-
5 cm = 2"
-
Three of my fingers together.
-
Rock.
-
Chicago Municipal Ordinance 8-24-020 specifies that those over 18 can carry a concealed knife blade no longer than 6.35 cm = 2.5", i.e. four of my fingertips together.
-
9 cm = 3.5"
-
The width of my palm (from heart line start to life line start). The traditional English unit of a palm = 7.62 cm = 3".
-
10 cm = 4"
-
The width of my hand with thumb flesh.
-
The width of my hand between my index finger tip and my middle finger tip if I splay them.
-
The width of my hand from the outside of my pink to the outside of my index finger if I relax my hand. The traditional English unit of a hand = 4/3 palm = 10.16 cm = 4".
-
Fist.
-
A CD or DVD is 12 cm =4.72"
-
15 cm = 6"
-
The span between my thumb tip and my index finger if I make a "gun" shape.
-
The span between my index finger tip and pink tip if I splay them.
-
Yawara stick.
-
Kubotan stick. Often a keychain. Originally without spikes or pointed tips. Popularized by Takayuki Kubota.
-
20 cm = 8"
-
The span between my thumb tip and pinky tip when I splay my hand. The traditional English unit of "span" = 22.86 cm = 9".
-
A DVD case is roughly 20 cm = 8" tall and 15 cm = 6" deep.
-
Pocket Knife.
-
30 cm = 1' == 12" = 1 shaku
-
Elbow to wrist.
-
My bare foot is 26 cm = 10", so my shoes are roughly 30 cm = 1' == 12".
-
Dagger.
-
A Tanto blade is less than 1 shaku = 11.93 inches = 30.30 cm.
-
A4 paper is 21.0 x 29.7 cm = 8.27 x 11.69 inches, i.e. the usual sqrt(2):2 ratio for ISO paper.
-
"Letter" paper is 21.6 x 27.9 cm = 8.5 x 11.0 inches.
-
40 cm = 1'4" == 16"
-
From my elbow to the end of a one-knuckle fist.
-
A Roundel Dagger is around 45 cm = 1'6" == 18". Fillipo Vadi recommended a length of a man's hand and forearm.
-
50 cm = 1'8" == 20"
-
Knee to heel.
-
Weapons such as Sai, Tonfa, or Kama can be held along the forearm and be able to extend a bit past both ends.
-
60 cm = 2' == 24"
-
From my armpit to my knuckles
-
Short Sword.
-
A Gladius blade ranged from 60-70 cm = 24-28".
-
A Wakizashi (aka Shoto) blade is 1-2 shaku = 30-60 cm = 1-2' == 12-24".
-
A Tambo or Tanbo stick/staff. The natural length can be held in the hand and fully extended downward without touching the ground.
-
70 cm = 2'4" == 28"
-
From my armpit to my fingertips.
-
Kali/Eskrima/Arnis Stick.
-
A suggested natural length for weapons like a kali stick is such that you can hold it and have the tip clear the ground plus have some of the handle stick out too.
-
80 cm = 2'8" == 32"
-
Up to my crotch.
-
A Spatha blade ranged from 75-100 cm = 30-39".
-
90 cm = 3' == 36"
-
Up to my belt.
-
A Hanbo or Sanshaku Bo or Suteki (walking stick) is 3 shaku = 90.9 cm = 36.8".
-
An American Half Staff is 91.44 cm = 3' == 36".
-
100 cm = 3'3" == 39"
-
Up to my belly button.
-
Arming/Fighting/Single-Handed Sword.
-
The wooden Arming Swords at WoodenSwords.com are 100 cm = 3'3" == 39" with 11 cm = 4.5" handles but go down to 90 cm = 3' == 36".
-
The aluminum I.33 Arming Swords at SwordCrafts.com are 102 cm = 3'4" == 40" with 80 cm = 2'8" == 32" blades.
-
Grand Baton, Single Stick, La Canne, Cane, Walking Stick.
-
A Daito (either a Katana or Tachi) blade is over 2 shaku = 60 cm = 2' == 24".
-
1 m == how far light travels in 1/299,792,458 of a second in a vacuum. The speed of light (c) in a vacuum is the definition upon which the meter is defined.
-
110 cm = 3'7" = 43"
-
Up to my lower ribs.
-
Roughly the longest blade I could comfortably draw from a scabbard at my waist, or keep the point on an opponent while holding him with my off hand.
-
'Of the length of weapons, and how every man may fit himself to the perfect length of his weapon, according to his own stature, with brief reasons wherefore they ought to be so. To know the perfect length of your sword, you shall stand with your sword and dagger drawn, as you see this picture, keeping out straight your dagger arm, drawing back your sword as far as conveniently you can, not opening the elbow joint of your sword arm, and look what you can draw within your dagger, that is the just length of your sword, to be made according to your own stature.' -George Silver [AEMMA.org/...].

-
120 cm = 3'11" == 47".
-
Up to my solar plexus.
-
Rapier, Jian (Tai Chi Sword), or Stick Grappling Stick.
-
A "3.9" Shinai is 3.9 shaku == 3 shaku 9 sun == 3.9 * (10/33) m = 1.1818 m = 46.528".
-
A Yonshaku Bo is 4 shaku = 1.2121 m = 47.721"
-
An American Jo Staff is 122 cm = 4' == 48".
-
A jung bong sul is a Korean "middle staff" and ranges from 110 cm = 43" to 130 cm = 51".
-
Long Sword
-
The wooden Long Swords at WoodenSwords.com are 122 cm = 4' == 48" with 19 cm = 7.5" handles but go down to 107 cm = 3'6" == 42".
-
The aluminum Liberi Long Swords at SwordCrafts.com are 117 cm = 3'10" == 46" with 90 cm = 3' == 36" blades.
-
130 cm = 4'3" = 51"
-
A Jo (Japanese 杖) is 4 shaku 2 sun 1 bu = 127.56 cm = 4'4.25" == 50.25". For a personal fit, a jo come to just under your armpit. Conveniently, this comes to 130 cm = 4'3" == 51".
-
A suggested natural overall length for a longsword is up to your armpit.
-
140 cm = 4'7" == 55"
-
Up to my shoulders.
-
Bastard Sword.
-
The wooden Great Swords at Woodenswords.com are 135 cm = 4'5" == 53" with 28 cm = 11" handles).
-
The aluminum Lichtenaur Long Swords at SwordCrafts.com are 132 cm = 4'4" == 52" with 102 cm = 3'4" = 40" blades.
-
150 cm = 4'11" == 59"
-
Up to my mouth.
-
A Goshaku Bo is 5 shaku = 1.5151 m = 59.651 inches
-
An American Short Staff or jogo do pau stick is 152 cm = 5' == 60".
-
160 cm = 5'3" == 63"
-
Up to my eyes.
-
Two-Handed Sword.
-
170 cm = 5'7" == 67"
-
Almost my height, 172 cm = 5'8" == 68".
-
The pollaxe or pole axe was man-height, i.e. any longer was shunned.
-
180 cm = 5'11" == 71".
-
Almost a fist above my head.
-
A Bo (Japanese 棒) or Rokkushaku Bo or Cho Bo is 6 shaku = 1.8182 m = 71.582 inches.
-
An American Bo Staff is 183 cm = 6' == 72".
-
Quarterstaff. Quarterstaff.org says the personalized size of a quarterstaff is supposed to be a fist above your head. Conveniently, this comes to 183 cm = 6' == 72".
-
190 cm = 6'3" == 75"
-
200 cm = 6'7" == 79"
-
My fingertips if my hand is raised up.
-
Staff. Some say the personalized size of a Staff is supposed to be as high as you can reach and cap with your fingertip while standing comfortably -- this comes to 198 cm = 6'6" == 78" which also happens to be a standard commercial staff height.
-
210 cm = 6'11" == 83"
-
220 cm = 7'3" == 87"
-
230 cm = 7'7" == 91"
-
240 cm = 7'11" == 95"
-
250 cm = 8'2" == 98"
-
Roughly an arm length above as high as I can reach.
-
'To know the perfect length of your short staff, or half pike, forest bill, partisan, or glaive, or such like weapons of vantage and perfect lengths, you shall stand upright, holding the staff upright close by your body, with your left hand, reaching with your right hand your staff as high as you can, and then allow to that length a space to set both your hands, when you come to fight, wherein you may conveniently strike, thrust, and ward, & that is the just length to be made according to your stature. And this note, that these lengths will commonly fall out to be eight or nine foot long, and will fit, although not just, the statures of all men without any hindrance at all unto them in their fight, because in any weapon wherein the hands may be removed, and at liberty, to make the weapon longer of shorter in fight at his pleasure, a foot of the staff being behind the backmost hand does no harm.' -George Silver [AEMMA.org/...]. This translates to roughly as high as you can reach plus the width of your grip.

-
260 cm = 8'6" == 102"
-
270 cm = 8'10" == 106"
-
280 cm = 9'2" == 110"
-
290 cm = 9'6" == 114"
-
300 cm = 9'10" == 118"
-
Regarding the mile
-
1 inch == 2.54 cm.
-
1 foot == 12 inches == 0.3048 m. Ignore the suckiness of 1 U.S. survey foot == 1200/3937 m.
-
1 yard == 3 feet == 0.9144 m. The yard was defined as 0.9144 m in 1958.
-
1 furlong == 220 yards
-
1 mile == 8 furlongs == 1760 yards == 5280 feet == 63360 inches = 1.609344 Km
-
1 acre == 4840 square yards
-
1 square mile == 1 section == 640 acres
-
1 township == 36 sections
-
Roman units for length (via Ancient Roman units of measurement [W])
-
1 digit == 1 digitus == 1/16 pes = 18.5 mm
-
1 palm == 1 palmus == 1/4 pes = 74 mm
-
1 foot == 1 pes = 296 mm.
-
1 cubit == 1 cubitus == 1.5 pes = 444 mm
-
1 step == 1 gradus == 2.5 pes = 0.74 m
-
1 pace == 1 passus == 5 pes = 1.48 m
-
1 perch == 1 pertica == 10 pes = 2.96 m
-
1 arpent == 1 actus == 120 pes = 35.5 m
-
1 stadion == 1 stadium == 625 pes = 185 m
-
1 mile == 1 millarium == 5000 pes = 1.48 Km
-
1 league == 1 leuga == 7500 pes = 2.2 Km. Other sources say 1 Roman league == 3 millas == 1500 pes = 4.4 Km. The "league", "leuga", hispanic "legua", "marine league", French "lieue", etc. is one of the ugliest units of measure that is sometimes a unit of length (roughly the distance walked in an hour) and sometimes a unit of area.
-
Nautical Units
-
"What is a knot? What is a nautical mile?"
-
'The device that sailors used to make their speed measurement was called the "chip log". Chip as in chip of wood, and log as in to record in a log. The chip was a wedge of wood about 18" in size; it was tied to one end of a rope on a large spool. The rope had knots tied into it about every 47'3" (more about how that was calibrated below).
The wooden chip was thrown overboard at the ship's stearn (back end). Because of its wedge shape, it would "grab" the water and start pulling out rope as the ship moved forward at some yet unknown speed. One man would hold the spool of rope as it played out; another man would start a sandglass filled with 30 seconds of sand; and a third man would count the knots as they passed over the stearn board. When the 30 seconds of sand expired, the time keeper would call out and the counting of knots would stop.
The faster the ship was sailing, more knots and a longer length of rope were played out. The number of knots in the rope that were counted in 30 seconds, then, was equal to the speed of the ship in nautical miles per hour. A "knot", therefore, is not a nautical mile, it is a nautical mile per hour. Thus 1 knot was equivalent to 1 nautical mile per hour; 5 knots were equivalent to 5 nautical miles per hour; etc. The similar sound of "knot" and "naut" is entirely coincidental.
Finally, what about the actual values of 47'3" between knots on the rope and the 30 seconds that were used with the chip log? The length was based on converting [1 nautical mile per hour] to [feet per second(fps)], and then multiplying [fps] by 30 seconds (which was a practical time to spend counting knots with a sandglass). The result was the calibrated length in feet at which to tie the knots for a 30-second run of the chip log.'
-
Fathoms
-
6 feet == 1 fathom. Fathoms have no "beautiful" relationship with nautical miles.
-
120 fathoms == 1 cable length
-
7.5 cables == 1 mile
-
5,280 feet == 1 statute mile
-
6,076 feet= = 1 nautical mile
-
880 fathoms == 1 mile
-
Nautical Miles
-
1 nautical mile == 1/60 of a degree == 1 minute of latitude = 1.15 miles = 1.852 Km
-
60 nautical miles == 1 degree == 1/360 of the circumference of Earth
-
3 nautical miles == 1 marine league
-
21,600 nautical miles == 360 degrees * (60 minutes/degree)
-
1 nautical mile/hour == 1 knot. Note that a knot measures velocity, not length. No puns intended.
-
Shaku (尺). [W 2005-03-11] The shaku is an archaic Japanese unit of length.
-
kujirajaku (whale shaku) was used for cloth and such. 1 kujirkjaku = 125/330 m = 37.9 cm = 14.9 inches.
-
kanejaku (metal shaku) was used for metal, wood, etc. The shaku was officially defined as 3.3 shaku == 1 m in 1891.
-
1 shaku == 10/33 m == 0.30303... m == 30.3030... cm = 11.930 in
-
1 shaku == 10 sun == 100 bu.
-
Gauge (ga). Most gauge measurements are inverse, i.e. larger gauge indicates smaller size, because historically a smaller size was obtained by more processing.
-
American Wire Gauge (AWG). Lengths below indicate diameter.
-
000000 (6/0) = 14.73 mm = 0.5800". Larger.
-
12 = 2.053 mm = 0.0808". Common.
-
40 = 0.07987 mm = 0.0031". Smaller.
-
Sheet metal gauges. Lengths below indicate thickness.
-
6 = 4.9352 mm steel = 0.1943" steel = 4.1148 mm aluminum = 0.1620" aluminum. Thicker.
-
16 = 1.5189 mm steel = 0.0598" steel = 1.2903 mm aluminum = 0.0508" aluminum.
-
26 = 0.4547 mm steel = 0.0179" steel = 0.4039 aluminum = 0.4039" aluminum. Thinner.
-
See shotgun gauges in my section on guns.
-
1 smoot == height of Olive R. Smoot == 5'7" = 1.7018 m. Smoot [W].
-
1 Km = 1 klick.
-
Regarding the article on the Metre [W] in Wikipedia and the "meter vs. metre" discussion. I love it! There are many nuances on the issue but the article was created as "metre", the meter is French in origin where it is spelled metre, the rest of the world spells it a metre, and we Americans may spell it meter but we haven't officially converted to it. Thus: I agree that in Wikipedia the article should be Metre. However on my own personal site, I've been used to spelling it as meter. I may however switch to spelling it as metre just to be antagonistic. Plus it will help to remember that the circumference of the Earth through the poles is roughly 40,000,000 metres.
2007-10-24 05:04:29Z