The SI unit of area is the square metre, which is considered an SI derived unit.

As seen from the definition, the derived SI units of angular momentum are newton meter seconds ( N · m · s or kg · m < sup > 2 </ sup > s < sup >− 1 </ sup >) or joule seconds ( J · s ).

The International System of Units does not define units for digital information but notes that the SI prefixes may be applied outside the contexts where base units or derived units would be used.

Although the candela is now defined in terms of the second ( an SI base unit ) and the watt ( a derived SI unit ), the candela remains a base unit of the SI system, by definition.

Within each table, the units are listed alphabetically, and the SI units ( base or derived ) are highlighted.

For example, the CGS derived unit of force is the dyne, equal to, while the SI derived unit of force is the newton,.

However, where derived units are needed, the SI ones are generally used and taught instead of the CGS ones today.

For example, a physics lab course might ask students to record lengths in centimetres, and masses in grams, but force ( a derived unit ) in newtons, a usage consistent with the SI system.

Expressing a CGS derived unit in terms of the SI base units, or vice versa, requires combining the scale factors that relate the two systems:

The exabyte ( derived from the SI prefix exa -) is a unit of information or computer storage equal to one quintillion bytes ( short scale ).

It is a derived SI unit for expressing quantity values of catalytic activity of enzymes and other catalysts.

Category: SI derived units

The time and date are derived from Avogadro's number, which is approximately 6. 02 × 10 < sup > 23 </ sup >, defining the number of particles ( atoms or molecules ) in one mole of substance, one of the seven base SI units.

A petabyte ( derived from the SI prefix peta-) is a unit of information equal to one quadrillion ( short scale ) bytes, or 1 billiard ( long scale ) bytes.

The unit was formerly an SI supplementary unit, but this category was abolished in 1995 and the radian is now considered an SI derived unit.

The International System of Units ( SI ) defines seven units of measure as a basic set from which all other SI units are derived.

# REDIRECT SI derived unit # Supplementary units

These other units are called SI derived units, for example, the SI derived unit of area is square metre ( m < sup > 2 </ sup >), and of density is kilograms per cubic metre ( kg / m < sup > 3 </ sup >).

The ampere ( SI unit symbol: A ), often shortened to amp, is the SI unit of electric current ( quantity symbol: I, i ) and is one of the seven SI base units.

The SI unit of charge, the coulomb, " is the quantity of electricity carried in 1 second by a current of 1 ampere ".

In the International System of Units ( SI ), the standard unit of area is the square metre ( written as m < sup > 2 </ sup >), which is the area of a square whose sides are one metre long.

The meter is defined to be a unit of proper length, but the SI definition does not specify the metric tensor to be used in determining it.

The SI unit of measurement of electric current, the ampere, is named after him.

* aw, or attowatt, an SI unit of power

In the International System of Units ( SI ), B is the symbol of the bel, a unit of logarithmic power ratios named after Alexander Graham Bell.

Considerable confusion exists about the meanings of the SI ( or metric ) prefixes used with the unit byte, especially concerning prefixes such as kilo ( k or K ) and mega ( M ) as shown in the chart Prefixes for bit and byte.

( Note that K is the SI unit for temperature ( kelvin ) and should not be confused with k, the SI prefix for kilo.

In scientific contexts the Btu has largely been replaced by the SI unit of energy, the joule, though it may be used as a measure of agricultural energy production ( Btu / kg ).

The candela ( or ; symbol: cd ) is the SI base unit of luminous intensity ; that is, power emitted by a light source in a particular direction, weighted by the luminosity function ( a standardized model of the sensitivity of the human eye to different wavelengths, also known as the luminous efficiency function ).

Only the product is required to calculate planetary positions for an ephemeris, which explains why ephemerides are calculated in astronomical units and not in SI units.

( SI explicitly prohibits this usage, stating that the prefixes only have the 1000-based meaning, and cannot be used as placeholders for other numbers, like

The other organisations that maintain the SI system, also known by their French initialisms are the General Conference on Weights and Measures () ( CGPM ) and the International Committee for Weights and Measures () ( CIPM ).

The most commonly used units for molarity are mol / L ( the official SI units are mol / m < sup > 3 </ sup >).

The SI unit for measuring the rate of flow of electric charge is the ampere, which is charge flowing through some surface at the rate of one coulomb per second.

This is because there is no one-to-one correspondence between electromagnetic units in SI and those in CGS, as is the case for mechanical units.

Starting in the 1880s, and more significantly by the mid-20th century, CGS was gradually superseded internationally for scientific purposes by the MKS ( metre – kilogram – second ) system, which in turn developed into the modern SI standard.

The units gram and centimetre remain useful as prefixed units within the SI system, especially for instructional physics and chemistry experiments, where they match the small scale of table-top setups.

Thus, for example, the CGS unit of pressure, barye, is related to the CGS base units of length, mass, and time in the same way as the SI unit of pressure, pascal, is related to the SI base units of length, mass, and time:

The SI unit of kilogram per cubic metre ( kg / m < sup > 3 </ sup >) and the cgs unit of gram per cubic centimetre ( g / cm < sup > 3 </ sup >) are probably the most common used units for density.

( The SI second as now used for UTC, when adopted, was already a little shorter than the current value of the second of mean solar time.

* Deca-( symbol da ), an SI prefix for a factor of 10

In this way, decisions made by the original designers of ephemeris time influenced the length of today's standard SI second, and in turn, this has a continuing influence on the number of leap seconds which have been needed for insertion into current broadcast time scales, to keep them approximately in step with mean solar time.

The unit of measurement for enthalpy in the International System of Units ( SI ) is the joule, but other historical, conventional units are still in use, such as the British thermal unit and the calorie.

The SI unit for specific enthalpy is joule per kilogram.

The SI unit for period is the second.

The units for magnetic flux Φ, which is the integral of magnetic field over an area, are the weber ( Wb ) in the SI and the maxwell ( Mx ) in the cgs system.