Definition and Usage of Newton-metre
- A newton-metre is the unit of torque or moment in the International System of Units (SI).
- It is equal to the torque resulting from a force of one newton applied perpendicularly to a moment arm that is one metre long.
- The unit is also used as a unit of work or energy, equivalent to the joule.
- The metre term represents the distance travelled or displacement in the direction of the force, not the perpendicular distance from a fulcrum.
- Torque and energy expressed in newton-metres can sometimes lead to confusion.

Relationship Between Newton-metre and Joule
- One newton-metre of torque is equivalent to one joule per radian.
- Newton-metres and joules are dimensionally equivalent in SI base units.
- The expression for one newton-metre is 1 Nm = 1 kg·m²/s².
- Distinguishing between torque and energy avoids misunderstandings.

Conversion Factors
- 1 kilogram-force metre is equal to 9.80665 Nm.
- 1 newton-metre is approximately equal to 0.73756215 pound-force-feet.
- 1 pound-foot is equal to 1.35581795 Nm.
- 1 ounce-inch is approximately equal to 7.06155181 mNm (millinewton-metres).
- 1 dyne-centimetre is equal to 10 Nm.

Related Concepts and Units
- Bending moment is a related concept to newton-metre.
- Spring scale is an instrument that measures forces in newtons.
- Torque tester is another related concept to newton-metre.
- Newton-second is the derived SI unit of impulse.
- The nonstandard notation Nm is sometimes used in certain fields.

References and Additional Information
- BIPM provides information on unit symbols.
- Eshbach's Handbook of Engineering Fundamentals mentions newton-metre as the basic unit of energy in SI units.
- The spring scale is a different instrument that measures forces in newtons.
- The concept of torque is related to newton-metre.
- The newton-second is another derived SI unit.

Newton-metre (Wikipedia)

For the instrument that measures forces in newtons, see Spring scale.

The newton-metre or newton-meter (also non-hyphenated, newton metre or newton meter; symbol N⋅m or N m) is the unit of torque (also called moment) in the International System of Units (SI). One newton-metre is equal to the torque resulting from a force of one newton applied perpendicularly to the end of a moment arm that is one metre long.

Newton-metre
One newton-metre is the torque resulting from a force of one newton applied perpendicularly to the end of a moment arm that is one metre long.
General information
Unit system	SI
Unit of	torque
Symbol	N⋅m, N m
Conversions
1 N⋅m in ...	... is equal to ...
FPS system	0.73756215 lbf.ft
inch⋅pound-force	8.8507 in lbf
inch⋅ounce-force	141.6 in oz

The unit is also used less commonly as a unit of work, or energy, in which case it is equivalent to the more common and standard SI unit of energy, the joule. In this usage the metre term represents the distance travelled or displacement in the direction of the force, and not the perpendicular distance from a fulcrum as it does when used to express torque. This usage is generally discouraged, since it can lead to confusion as to whether a given quantity expressed in newton-metres is a torque or a quantity of energy. However, since torque represents energy transferred or expended per angle of revolution, one newton-metre of torque is equivalent to one joule per radian.

Newton-metres and joules are dimensionally equivalent in the sense that they have the same expression in SI base units,

${\displaystyle 1\,{\text{N}}{\cdot }\mathrm {m} =1\,{\frac {{\text{kg}}{\cdot }{\text{m}}^{2}}{{\text{s}}^{2}}}\quad ,\quad 1\,\mathrm {J} =1\,{\frac {\mathrm {kg} {\cdot }\mathrm {m} ^{2}}{\mathrm {s} ^{2}}}}$

but are distinguished in terms of applicable kind of quantity, to avoid misunderstandings when a torque is mistaken for an energy or vice versa. Similar examples of dimensionally equivalent units include Pa versus J/m³, Bq versus Hz, and ohm versus ohm per square.