Unit Converter (Metric system, US customary units, etc.) / Tool

This is a unit converter that runs in your browser. Interconvert metric, United States customary units / Imperial units, and other systems of units with other systems of units.

• Entering a value in any unit will automatically convert it to another unit.
• Rounded to the fourteenth decimal place.
• A number with many digits may appear as 1e9. This is the computer’s exponential representation, where “e” is a power of 10.
  e.g. 1e3 = 10³ = 1,000
  e.g. 1e-3 = 10^-3 = 0.001
• This tool does not check the lower limit, so even if it is less than 0 Kelvin, it will be converted without error. Please note.

Metric unit conversion

The metric system is a system of units based on the meter as a unit of length and the kilogram as a unit of mass.

Non-SI unit of length: Nautical mile conversion

Historically, it was defined as the meridian arc length corresponding to one minute (1/60 of a degree) of latitude. Today the international nautical mile is defined as exactly 1,852 metres (6,076 ft; 1.151 mi).

$1nm = 1852m$

Non-SI units of area: Hectare / Are conversion

One hectare is 10,000 square meters and one hectare is 100 square meters, but neither is an SI unit.

Units	Symbols	Conversion
Are Square decametre	a dam2	102 m2
Hectare Square hectometre	ha hm2	104 m2
Square kilometre	km2	106 m2

Non-SI units of volume: Liter conversion

One liter is defined as the volume of a cube of 10 cm on each side (= 1dm³).

Units	Symbols	Conversion	Metric conversion
Microliter	µL	10−6 L	1 mm3
Milliliter	mL	10−3 L	1 cm3
Centiliter	cL	10−2 L	101 cm3
Deciliter	dL	10−1 L	102 cm3
Liter	L	100 L	103 cm3 (1 dm3)
Decaliter	daL	101 L	104 cm4 (101 dm3)
Hectoliter	hL	102 L	105 cm5 (12 dm3)
Kiloliter	kL	103 L	1 m3
Megaliter	ML	106 L	103 m3

United States customary units / Imperial units conversion

The United States customary units / Imperial units is a system of units used mainly in the United States, with the yard as the basic unit of length and the pound as the basic unit of mass.

Units	Symbols	Conversion	Metric conversion
Inch	in		25.4 mm
Foot	ft	12 in	30.48 cm
Yard	yd	3 ft	0.9144 m
Chain	ch	22 yd	20.1168 m
Furlong	fur	220 yd	201.168 m
Mile	mi	1760 yd	1609.344 m

Units	Symbols	Conversion	Metric conversion
Grain	gr		0.06479891 g
Dram	dr	27 × 11/32 gr	1.7718451953125 g
Ounce	oz	16 dr	28.349523125 g
Pound	lb	16 oz	0.45359237 kg
Hundredweight (US)	cwtUS	100 lb	45.359237 kg
Ton (US)	s.t.	2000 lb	907.18474 kg
Stone (UK)	st	14 lb	6.35029318 kg
Quarter (UK)	qtr	28 lb	12.70058636 kg
Hundredweight (UK)	cwtUK	112 lb	50.80234544 kg
Ton (UK)	l.t.	2240 lb	1016.0469088 kg

In addition, different units are used in the U.S. and the U.K. for volume.

Volume of liquids (US) conversion

Units	Symbols	Definitions	Liter
Fluid dram (US)	fl.dr.	1/8 fl.oz.	3.6966911953125 mL
Fluid ounce (US)	fl.oz.	1/16 pt	29.5735295625 mL
Pint (US)	pt	1/2 qt	473.176473 mL
Quart (US)	qt	1/4 gal	0.946352946 L
Gallon (US)	gal	231 cu.in.	3.785411784 L
Oil barrel	bbl		158.987294928 L

※バレルは石油以外では定義が異なります。

Volume of liquids (UK) conversion

Units	Symbols	Definitions	Liter
Fluid dram (UK)	fl.dr.	1/8 fl.oz.	3.5516328125 mL
Fluid ounce (UK)	fl.oz.	1/5 gal	28.4130625 mL
Pint (UK)	pt	1/2 qt	568.26125 mL
Quart (UK)	qt	1/4 gal	1.1365225 L
Gallon (UK)	gal		4.54609 L

Japanese units of measurement (shaku–kan system) conversion

The shaku–kan system is a traditional Japanese units of measurement , with the basic unit being the shaku for length and the kan for mass.

• Length: The basic unit is the “shaku (尺)“. 1 shaku is defined as 10/33 of a meter.
• Mass: The basic unit is the “kan (貫)“. 1 kan is defined as 3.75 kg.
• Area: The basic unit is the “tsubo (坪)“. 1 tsubo is defined as 400/121 of a m².
• Volume: The basic unit is the “shō (升)“. 1 shō is defined as 2401/1331000 of a m³.

Units	Conversion	Metric conversion
寸 sun	0.1尺	1/33 m (≈30.3030 mm)
尺 shaku		10/33 m (≈30.3030 cm)
丈 jō	10尺	100/33 m (≈3.03030 m)
間 ken	6尺	60/33 m (≈1.81818 m)
町 chō	60間	1200/11 m (≈109.09 m)
里 ri	36町	43200/11 m (≈3927.273 m)

Units	Conversion	Metric conversion
匁 momme		3.75 g
両 ryō	10匁	37.5 g
斤 kin	16両	600 g
貫 kan	100両	3.75 kg

Units	Conversion	Metric conversion
勺 shaku	1/10合	4/121 m2 (≈330.58 cm2)
合 gō	1/10坪	40/121 m2 (≈0.33058 m2)
坪/歩 tsubo		400/121 m2 (≈3.3058 m2)
畝 se	30坪	12000/121 m2 (≈99.174 m2)
反 tan	10畝	120000/121 m2 (≈991.736 m2)
町 chō	10反	1200000/121 m2 (≈9917.355 m2)
畳/帖 jō		1.62 m2

Units	Conversion	Metric conversion
勺 shaku	1/10合	≈18.039 mL
合 gō	1/10升	≈180.391 mL
升 shō		≈1.804 L (2401/1331000 m3)
斗 to	10升	≈18.039 L
石 koku	10斗	≈180.391 L

Unit of force conversion

The unit of force in the International System of Units (SI) is the newton.

Units	Symbols	Definitions
Newton	N	The force which gives a mass of 1 kg an acceleration of 1 m/s2.
Dyne	dyn	The force which gives a mass of 1 g an acceleration of 1 cm/s2.
Kilogram-force	kgf	The magnitude of the force exerted on a mass of 1 kg under normal gravity.
Pound-force	lbf	Equal to the gravitational force exerted on a mass of 1 lb on the surface of Earth.
Poundal	pdl	Defined as the force necessary to accelerate 1 pound-mass at 1 ft/s2.

The conversion formula is as follows

$1 N = 1 kg·m/s^2$

$1 dyn = 10^{-5} N$

$1 kgf = 9.80665 N$

$1 lbf = 4.4482216152605 N$

$1 pdl = 0.138254954376 N$

Unit of pressure conversion

The unit of force in the International System of Units (SI) is the pascal.

Units	Symbols	Definitions
Pascal	Pa	1 Pa is the pressure exerted by a force of magnitude 1 N perpendicularly upon an area of 1 m2.
Bar	bar	Equal to 100 kPa.
Standard atmosphere	atm	International standard for atmospheric pressure.
Technical atmosphere	at	Equal to 1 kgf/cm2.
Torr	Torr	1/760 of standard atmosphere.
Millimetre of mercury	mmHg	Same as tor.
Meter of water	mH2O	Water pressure at 1 m depth.
Inch of water	inH2O	Water pressure at 1 in depth
Pound per square inch	psi	Pressure or stress exerting a force of 1 N per 1 sq.in.

The conversion formula is as follows

$1 bar = 10^5 Pa = 100 kPa$

$1 atm = 101325 Pa$

$1 at = 98066.5 Pa$

$1 Torr = 1 mmHg = {\dfrac {1}{760}} atm = {\dfrac {101325}{760}} Pa \approx 133.322 Pa$

$1 mH_2O = 10^2 cmH_2O = 10^3 mmH_2O = 9806.65 Pa$

$1 inH_2O = {\dfrac {1}{12}} ftH_2O = 249.0899 Pa$

$1 psi = 6894.76 Pa$

Unit of energy conversion

The unit of force in the International System of Units (SI) is the joule.

Units	Symbols	Definitions
Joule	J	Work done when a force of 1 N moves an object 1 m.
Erg	erg	Work done when a force of 1 dyn moves an object 1 cm.
Kilogram-force	kgf·m	Work done when a force of 1 kgf moves an object 1 m.
Foot-poundal	ft·pdl	Work done when a force of 1 pdl moves an object 1 ft.
Foot-pound	ft·lbf	Work done when a force of 1 lbf moves an object 1 ft.
Kilowatt-hour	kW·h	1000 times more work at a power rate of 1 W per hour. (3600 times that of J)
Calorie	cal	Heat to raise the temperature of 1 g of water by 1 °C.
British thermal unit	Btu	Heat to raise the temperature of 1 lb of water by 1 °C.
Electronvolt	Btu	Kinetic energy gained by an electron by passing a potential difference of 1 V in vacuum.
TNT equivalent	t	Explosive power of 1 ton of TNT.

The conversion formula is as follows

$1 erg = 10^{-7} J$

$1 cal_{th} = 4.184 J$

$1 cal_{IT} = 4.1868 J$

$1 kgf·m = 9.80665 J$

$1 ft·pdl = 0.0421401100938048 J$

$1 ft·lbf = 1.3558179483314004 J$

$1 kW·h = 3.6 \times 10^6 J = 3.6 MJ$

$1 Btu = 1055.05585262 J$

$1 eV = 1.602176634 \times 10^{-19} J$

$1 t = 4.184 \times 10^9 J$

Unit of temperature conversion

The unit of force in the International System of Units (SI) is the kelvin.

Units	Symbols	Definitions
Kelvin	K	1/100 of the temperature difference between the boiling and freezing points of water.
Celsius	°C	Kelvin - 273.15
Fahrenheit	°F	The freezing point of fresh water is 32 degrees, the boiling point is 212 degrees, and the interval between them is divided into 180 equal parts to make 1 degree.
Rankine	°R	A unit of temperature in the same temperature interval as Fahrenheit, with absolute zero being 0.
Delisle	°De	Unit of boiling point of water is 0 degrees and freezing point is 150 degrees.
Newton	°N	Unit where the temperature when snow melts is 0 degrees and the temperature when water boils is 33 degrees.
Réaumur	°Ré	A unit of temperature that is rarely used today.
Rømer	°Rø	A unit of temperature that is rarely used today.

The conversion formula is as follows

$0 K = \text{Absolute zero}$

$[°C] = [K] - 273.15$

$[°F] = [K] \times {\dfrac {9}{5}} - 459.67$

$[°F] = [°C] \times {\dfrac {9}{5}} + 32$

$[°R] = [°K] \times {\dfrac {9}{5}}$

$[°De] = (100 - [°C]) \times {\dfrac {3}{2}}$

$[°N] = [°C] \times {\dfrac {33}{100}}$

$\text{[°Ré]} = [°C] \times {\dfrac {4}{5}}$

$\text{[°Rø]} = [°C] \times {\dfrac {21}{40}} + 7.5$

Unit of time conversion

The unit of force in the International System of Units (SI) is the seconds.

Units	Converted value	Units	Converted value
1 year	365 days	1 day	24 hours
1 month	30 days	1 hour	60 minutes
1 week	7 days	1 minutes	60 seconds

Unit of tatami mats conversion

Jō (帖, 畳) is a unit of measurement used to express the floor area of a room.

Jō (帖)

“畳” varies in size, but “帖” is clearly defined as 1.62 square meters.

Jō (畳)

There are multiple types of “畳” dimensions, and the area varies depending on which dimension “畳” is based on. There seem to be two reasons for the creation of multiple types.

1. The standard 1間 (ken) dimension varies from period to period and region to region.
2. Whether tatami split (based on tatami) or pillar split (based on pillar) varies by period and region.

Name	Split	1間	Size	Area
Kyōma	Tatami split	6尺3寸	3尺1寸5分×6尺3寸	≈1.82405 m2
Chūkyōma	Tatami split	6尺	3尺×6尺	≈1.6562 m2
Edoma	Pillar split	6尺	≈2尺9寸×5尺8寸	≈1.5488 m2
Danchima	-	5尺6寸	2尺8寸×5尺6寸	≈1.445 m2
6-2 ma	-	6尺2寸	3尺1寸×6尺2寸	≈1.7672 m2
6-1 ma	-	6尺1寸	3尺5分×6尺1寸	≈1.71125 m2

Unit of bit/byte conversion

$1byte = 8bit$

$1KB = 1024byte$

$1MB = 1024KB = 1024^2byte$

1 KB is 1024 Bytes? or 1000 Bytes?

This tool converts 1 kilobyte (KB) to 1024 bytes.

But originally kilo is $10^3$. These are called metric prefixes.

Metric prefix	Name	Base 10
K	kilo	$10^3$ = 1,000
M	mega	$10^6$ = 1,000,000
G	giga	$10^9$ = 1,000,000,000
T	tera	$10^{12}$ = 1,000,000,000,000
P	peta	$10^{15}$ = 1,000,000,000,000,000
E	exa	$10^{18}$ = 1,000,000,000,000,000,000
Z	zetta	$10^{21}$ = 1,000,000,000,000,000,000,000
Y	yotta	$10^{24}$ = 1,000,000,000,000,000,000,000,000

But since computers are binary numbers, $10^n$ is inconvenient.

$1bit = 2^1 = 2$
$2bit = 2^2 = 4$
$3bit = 2^3 = 8$
…
$8bit = 2^8 = 256$
$9bit = 2^9 = 512$
$10bit = 2^{10} = 1024$

Therefore, the computer decided as follows.

• KB: 1,024byte
• MB: 1,024KB
• GB: 1,024MB

But this conversion method is often confusing. It is recommended to use a binary prefix to ensure a distinction.

Binary prefix	Name	Base 10
Ki	kibi	$2^{10}$ = 1,024
Mi	mebi	$2^{20}$ = 1,048,576
Gi	gibi	$2^{30}$ = 1,073,741,824
Ti	tebi	$2^{40}$ = 1,099,511,627,776
Pi	pebi	$2^{50}$ = 1,125,899,906,842,624
Ei	exbi	$2^{60}$ = 1,152,921,504,606,846,976
Zi	zebi	$2^{70}$ = 1,180,591,620,717,411,303,424
Yi	yobi	$2^{80}$ = 1,208,925,819,614,629,174,706,176