The

**SI base units**and their physical**quantities**are the metre for measurement of**length**, the**kilogram**for**mass**, the second for time, the ampere for electric current, the kelvin for temperature, the candela for**luminous intensity**, and the mole for amount of substance.1

## What is a basic unit?

Any of the

**fundamental units**of length, mass, time, electric current, thermodynamic temperature, amount of substance, or luminous intensity in the International System of**Units**, consisting respectively of the meter, kilogram, second, ampere, kelvin, mole, and candela.2

## What are the base units of the SI system?

**SI Base Units**

- The ampere (A) The ampere is the SI base unit of electrical current.
- The candela (cd) The candela is the SI base unit of luminous intensity.
- The kelvin (K) The kelvin is the SI base unit of thermodynamic temperature.
- The kilogram (kg) The kilogram is the SI base unit of mass.
- The metre (m)
- The mole (mol)
- The second (s)

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## What is the unit of weight in the metric system?

**gram**( ) The basic unit of

**mass**in the metric system, equal to 1,000 grams (2.2 pounds). See Table at measurement. See Note at weight. metric system A decimal system of weights and measures based on the meter as a unit of length, the

**kilogram**as a unit of

**mass**, and the liter as a unit of volume.

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## What are the units of measurement in the metric system?

The

**metric system**is an alternative**system of measurement**used in most countries, as well as in the United States. The**metric system**is based on joining one of a series of prefixes, including kilo-, hecto-, deka-, deci-, centi-, and milli-, with a base unit of**measurement**, such as meter, liter, or gram.5

## What is the unit of time?

The

**base unit**for time is the**second**(the other SI units are: metre for length, kilogram for mass, ampere for electric current, kelvin for temperature, candela for luminous intensity, and mole for the amount of substance).6

## What is the SI unit of weight?

The unit of measurement for weight is that of force, which in the International System of Units (SI) is the

**newton**. For example, an object with a mass of one**kilogram**has a weight of about 9.8**newtons**on the surface of the Earth, and about one-sixth as much on the Moon.7

## What is a unit of length?

Units of Length. Recall that the most common metric units of length used are the kilometre (km), the

**metre**(m), the centimetre (**cm**) and the millimetre (mm).8

## What units are used to measure volume in the metric system?

The base

**units of length**and volume are linked in the metric system. By definition, a**liter**is equal to the volume of a cube exactly 10 cm tall, 10 cm long, and 10 cm wide. Because the volume of this cube is 1000 cubic centimeters and a**liter**contains 1000**milliliters**, 1**milliliter**is equivalent to 1 cubic**centimeter**.9

## What is the SI unit of length?

The SI unit for length is meters(m), for

**mass**is kilograms(kg), for**volume**is cubic**meter**(m^3), for**density kilogram**per cubic**meter**(kg/m^3), for time is seconds(s), and for temperature is kelvins(K).12

## What is the basic unit of mass in the SI system?

The

**kilogram**is the SI base unit of mass and is equal to the mass of the international prototype of the**kilogram**, a platinum-iridium standard that is kept at the International Bureau of Weights and Measures (BIPM) .13

## What is the SI unit used to measure distance?

Every system of measures, such as the SI (metric ) system has a standard unit for most measurements. The SI “standard” unit for distance if the

**meter**. In the vLength conversion calculator you will find at least seven SI units of length or distance.14

## What is the unit of temperature in the English system?

Definition

Dimension | English Engineering unit | SI unit |
---|---|---|

length | foot (ft) | meter (m) |

mass | pound mass (lb) | kilogram (kg) |

force | pound force (lbf) | newton (N) |

temperature | degree Fahrenheit (°F) | degree Celsius (°C) |

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## What is imperial system of units?

Most countries use the Metric

**System**, which uses the measuring units such as meters and grams and adds prefixes like kilo, milli and centi to count orders of magnitude. In the United States, we use the older**Imperial system**, where things are measured in feet, inches and pounds.17

## What is the SI unit of acceleration?

Calculating acceleration involves dividing velocity by time — or in terms of units, dividing meters per

**second**[m/s] by**second**[s]. Dividing distance by time twice is the same as dividing distance by the square of time. Thus the SI unit of acceleration is the**meter**per**second**squared.