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

Metric system
angstrom
nanometre
nm
micrometre
μm
millimetre
mm
centimetre
cm
metre
m
kilometre
km
United States customary units / Imperial units
inch
in
foot
ft
yard
yd
chain
ch
furlong
fur
mile
mi
Japanese units of measurement
sun
shaku
ken
chō
ri
Nautical
nautical mile
nm / M

## How to use this 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.

Units Symbols Conversion
Nanometre nm 10-9 m
Micrometre μm 10-6 m
Millimetre mm 10-3 m
Centimetre cm 10-2 m
Decimetre dm 10-1 m
Decametre dam 101 m
Hectometre hm 102 m
Kilometre km 103 m
Megametre Mm 106 m
Units Symbols Conversion
Nanogram ng 10-9 g
Microgram μg 10-6 g
Milligram mg 10-3 g
Centigram cg 10-2 g
Decigram dg 10-1 g
Decagram dag 101 g
Hectogram hg 102 g
Kilogram kg 103 g
Megagram
tonne
Mg
t
106 g

### 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

sun
0.1尺 1/33 m
(≈30.3030 mm)

shaku
10/33 m
(≈30.3030 cm)

10尺 100/33 m
(≈3.03030 m)

ken
6尺 60/33 m
(≈1.81818 m)

chō
60間 1200/11 m
(≈109.09 m)

ri
36町 43200/11 m
(≈3927.273 m)
Units Conversion Metric conversion

momme
3.75 g

ryō
10匁 37.5 g

kin
16両 600 g

kan
100両 3.75 kg
Units Conversion Metric conversion

shaku
1/10合 4/121 m2
(≈330.58 cm2)

1/10坪 40/121 m2
(≈0.33058 m2)

tsubo
400/121 m2
(≈3.3058 m2)

se
30坪 12000/121 m2
(≈99.174 m2)

tan
10畝 120000/121 m2
(≈991.736 m2)

chō
10反 1200000/121 m2
(≈9917.355 m2)

1.62 m2
Units Conversion Metric conversion

shaku
1/10合 ≈18.039 mL

1/10升 ≈180.391 mL

shō
≈1.804 L
(2401/1331000 m3)

to
10升 ≈18.039 L

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.

$1\text{帖} = 1.62 m^2$

### 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