|Unit system||CGS units|
|1 dyn in ...||... is equal to ...|
|CGS base units||1 g⋅cm/s2|
|SI units||10−5 N|
|British Gravitational System||2.248089×10−6 lbf|
The dyne (symbol: dyn; from Ancient Greek δύναμις (dúnamis) 'power, force') is a derived unit of force specified in the centimetre–gram–second (CGS) system of units, a predecessor of the modern SI.
The name dyne was first proposed as a CGS unit of force in 1873 by a Committee of the British Association for the Advancement of Science. 
The dyne is defined as "the force required to accelerate a mass of one gram at a rate of one centimetre per second squared".  An equivalent definition of the dyne is "that force which, acting for one second, will produce a change of velocity of one centimetre per second in a mass of one gram". 
One dyne is equal to 10 micronewtons, 10−5 N or to 10 nsn (nano sthenes) in the old metre–tonne–second system of units.
|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 kilogram-force (9.80665 m/s2) is used here for all gravitational units.|
The dyne per centimetre is a unit traditionally used to measure surface tension. For example, the surface tension of distilled water is 71.99 dyn/cm at 25 °C (77 °F).  (In SI units this is 71.99×10−3 N/m or 71.99 mN/m.)