Newton (unit)
newton  
Visualization of one newton of force 

General information  
Unit system  SI 
Unit of  force 
Symbol  N 
Named after  Sir Isaac Newton 
Conversions  
1 N in …  … is equal to … 
SI base units  1 kg⋅m⋅s−2 
CGS units  105 dyn 
Imperial units  0.224809 lbf 
The newton (symbol: N) is the unit of force in the International System of Units (SI). It is defined as 1 kg⋅m/s2, the force which gives a mass of 1 kilogram an acceleration of 1 metre per second per second. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton’s second law of motion.
Definition[edit]
A newton is defined as 1 kg⋅m/s2 (it is a derived unit which is defined in terms of the SI base units).[1] One newton is therefore the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force.[2] The units “metre per second squared” can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by 1 metre per second every second.
In 1946, the Conférence Générale des Poids et Mesures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be the amount needed to accelerate 1 kilogram of mass at the rate of 1 metre per second squared. In 1948, the 9th CGPM Resolution 7 adopted the name newton for this force.[3] The MKS system then became the blueprint for today’s SI system of units. The newton thus became the standard unit of force in the Système international d’unités (SI), or International System of Units.
The newton is named after Isaac Newton. As with every SI unit named for a person, its symbol starts with an upper case letter (N), but when written in full it follows the rules for capitalisation of a common noun; i.e., “newton” becomes capitalised at the beginning of a sentence and in titles, but is otherwise in lower case.
In more formal terms, Newton’s second law of motion states that the force exerted on an object is directly proportional to the acceleration hence acquired by that object, thus:[4]
where represents the mass of the object undergoing an acceleration . As a result, the newton may be defined in terms of the kilogram (), metre (), and second () as
Examples[edit]
At average gravity on Earth (conventionally, g = 9.80665 m/s2), a kilogram mass exerts a force of about 9.8 newtons.
 An averagesized apple at 200 g, exerts about two newtons of force at Earth’s surface, which we measure as the apple’s weight on Earth.
 0.200 kg × 9.80665 m/s2 = 1.961 N.
 An average adult exerts a force of about 608 N on Earth.
 62 kg × 9.80665 m/s2 = 608 N (where 62 kg is the world average adult mass).[5]
Kilonewtons[edit]
It is common to see forces expressed in kilonewtons (kN), where 1 kN = 1000 N. For example, the tractive effort of a Class Y steam train locomotive and the thrust of an F100 jet engine are both around 130 kN.
One kilonewton, 1 kN, is equivalent to 102.0 kgf, or about 100 kg of load under Earth gravity.
 1 kN = 102 kg × 9.81 m/s2.
So for example, a platform that shows it is rated at 321 kilonewtons (72,000 lbf) will safely support a 32,100kilogram (70,800 lb) load.
Specifications in kilonewtons are common in safety specifications for:
 the holding values of fasteners, Earth anchors, and other items used in the building industry;
 working loads in tension and in shear;
 rockclimbing equipment;
 thrust of rocket engines, Jet engines and launch vehicles;
 clamping forces of the various moulds in injectionmoulding machines used to manufacture plastic parts.
Conversion factors[edit]
newton  dyne  kilogramforce,
kilopond 
poundforce  poundal  
1 N  ≡ 1 kg⋅m/s2  = 105 dyn  ≈ 0.10197 kp  ≈ 0.22481 lbf  ≈ 7.2330 pdl 
1 dyn  = 10–5 N  ≡ 1 g⋅cm/s2  ≈ 1.0197×10−6 kp  ≈ 2.2481×10−6 lbf  ≈ 7.2330×10−5 pdl 
1 kp  = 9.80665 N  = 980665 dyn  ≡ gn × 1 kg  ≈ 2.2046 lbf  ≈ 70.932 pdl 
1 lbf  ≈ 4.448222 N  ≈ 444822 dyn  ≈ 0.45359 kp  ≡ gn × 1 lb  ≈ 32.174 pdl 
1 pdl  ≈ 0.138255 N  ≈ 13825 dyn  ≈ 0.014098 kp  ≈ 0.031081 lbf  ≡ 1 lb⋅ft/s2 
The value of gn as used in the official definition of the kilogramforce (9.80665 m/s2) is used here for all gravitational units. 
Base  Force  Weight  Mass  
2nd law of motion  m = F/a  F = W ⋅ a/g  F = m ⋅ a  
System  BG  GM  EE  M  AE  CGS  MTS  SI 
Acceleration (a)  ft/s2  m/s2  ft/s2  m/s2  ft/s2  Gal  m/s2  m/s2 
Mass (m)  slug  hyl  poundmass  kilogram  pound  gram  tonne  kilogram 
Force (F),
weight (W) 
pound  kilopond  poundforce  kilopond  poundal  dyne  sthène  newton 
Pressure (p)  pound per square inch  technical atmosphere  poundforce per square inch  standard atmosphere  poundal per square foot  barye  pieze  pascal 
Prefix name  N/A  deca  hecto  kilo  mega  giga  tera  peta  exa  zetta  yotta  ronna  quetta 
Prefix symbol  da  h  k  M  G  T  P  E  Z  Y  R  Q  
Factor  100  101  102  103  106  109  1012  1015  1018  1021  1024  1027  1030 
Prefix name  N/A  deci  centi  milli  micro  nano  pico  femto  atto  zepto  yocto  ronto  quecto 
Prefix symbol  d  c  m  μ  n  p  f  a  z  y  r  q  
Factor  100  10−1  10−2  10−3  10−6  10−9  10−12  10−15  10−18  10−21  10−24  10−27  10−30 
See also[edit]
 Force gauge
 International System of Units (SI)
 Joule, SI unit of energy, 1 newton exerted over a distance of 1 metre
 Kilogramforce, force exerted by Earth’s gravity at sea level on one kilogram of mass
 Kip (unit)
 Pascal, SI unit of pressure, 1 newton acting on an area of 1 square metre
 Orders of magnitude (force)
 Pound (force)
 Sthène
 Newton metre, SI unit of torque
References[edit]
 ^ The International System of Units – 9th edition – Text in English (9 ed.). Bureau International des Poids et Mesures (BIPM). 2019. p. 137.
 ^ “Newton  unit of measurement”. Encyclopedia Britannica. Archived from the original on 20190927. Retrieved 20190927.
 ^ International Bureau of Weights and Measures (1977), The International System of Units (3rd ed.), U.S. Dept. of Commerce, National Bureau of Standards, p. 17, ISBN 0745649742, archived from the original on 20160511, retrieved 20151115.
 ^ “Table 3. Coherent derived units in the SI with special names and symbols”. The International System of Units (SI). International Bureau of Weights and Measures. 2006. Archived from the original on 20070618.
 ^ Walpole, Sarah Catherine; PrietoMerino, David; Edwards, Phillip; Cleland, John; Stevens, Gretchen; Roberts, Ian (2012). “The weight of nations: an estimation of adult human biomass”. BMC Public Health. 12 (12): 439. doi:10.1186/1471245812439. PMC 3408371. PMID 22709383.
 ^ Comings, E. W. (1940). “English Engineering Units and Their Dimensions”. Industrial & Engineering Chemistry. 32 (7): 984–987. doi:10.1021/ie50367a028.
 ^ Klinkenberg, Adrian (1969). “The American Engineering System of Units and Its Dimensional Constant gc”. Industrial & Engineering Chemistry. 61 (4): 53–59. doi:10.1021/ie50712a010.