Force Converter
Convert Newtons (N), Dynes (dyn), Pound-force (lbf), Kilogram-force (kgf), Poundals (pdl).
Result
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Base Unit
Relative Value
*Diagram shows values relative to the selected base unit (Newton).
Unit Information
What are Newtons (N)?
The Newton (symbol: N) is the SI derived unit of force. It is named after Sir Isaac Newton in recognition of his work on classical mechanics. One newton is defined as the force required to accelerate a mass of one kilogram by one meter per second squared (1 N = 1 kg·m/s²). Newtons are the standard unit for force in scientific and engineering calculations worldwide.
What is Pound-force (lbf)?
Pound-force (symbol: lbf, or sometimes lb-f) is a unit of force used in some systems, including English Engineering units and the British Gravitational system. One pound-force is the gravitational force exerted on a mass of one avoirdupois pound on the surface of Earth (at standard gravity). It is equivalent to approximately 4.44822 newtons. It's often used in the US for specifying tensions, thrusts, and loads.
What is Kilogram-force (kgf)?
Kilogram-force (kgf), also known as a kilopond (kp), is a gravitational unit of force. It's the force exerted by Earth's gravity on a mass of one kilogram. 1 kgf is approximately 9.80665 N. It's an older unit but is sometimes still seen in certain contexts.
What is a Dyne (dyn)?
The dyne is the unit of force in the CGS (centimeter–gram–second) system. One dyne is the force required to accelerate a mass of one gram by one centimeter per second squared. It is a very small unit, with 1 Newton equal to 100,000 dynes.
What is a Poundal (pdl)?
The poundal is the unit of force in the absolute foot–pound–second system of units. It is defined as the force necessary to accelerate a 1-pound mass at a rate of 1 foot per second squared. It is an absolute unit of force, unlike the pound-force, which is gravitational.
Formulas
1 lbf ≈ 4.44822 N
To convert pound-force to Newtons, multiply by approximately 4.44822.
1 N ≈ 0.22481 lbf
To convert Newtons to pound-force, multiply by approximately 0.22481.
1 kgf ≈ 9.80665 N
A kilogram-force (kgf or kilopond, kp) is the force exerted by Earth's gravity on a one-kilogram mass.
Force = mass × acceleration (F=ma)
Newton's Second Law of Motion, the fundamental relationship between force, mass, and acceleration.
1 N = 100,000 dynes
The relationship between the SI unit of force and the older CGS unit.
Key Reference Points
- Force to lift a small apple (mass ~100g or 0.1kg): ~1 Newton (0.98 N).
- Weight of an average adult male (mass ~70kg): ~686 Newtons or ~154 pound-force.
- Thrust of a commercial jet engine at takeoff: Can exceed 400,000 Newtons (400 kN).
- A strong human punch: Can generate over 2,000 Newtons.
- Clamping force of a large industrial vise: Can exceed 50,000 Newtons (50 kN).
- Weight of a gallon of water: ~8.34 lbf.
- A typical car's braking force: Can be several thousand lbf.
- Thrust of the Saturn V rocket's first stage: Over 7.6 million lbf.
- Tension in a guitar string: Typically 10-20 lbf.
- Force exerted by a professional powerlifter deadlifting 500 lbs: 500 lbf.
Did You Know?
The dyne is the CGS (centimeter-gram-second) unit of force, equal to 10⁻⁵ N. It's a very small unit. The poundal (pdl) is the unit of force in the absolute foot–pound–second system of units, defined as the force necessary to accelerate a 1-pound mass by 1 foot/second². Both are less common now but have historical significance.
Force is a vector quantity, meaning it has both magnitude (how much force) and direction. This is crucial in physics for determining the net effect of multiple forces acting on an object.
'G-force' is a measure of acceleration experienced by an object, expressed as a multiple of the acceleration due to gravity (g ≈ 9.8 m/s²). For example, 2 Gs means experiencing an acceleration twice that of gravity.
Physics recognizes four fundamental forces of nature: the strong nuclear force, the weak nuclear force, electromagnetism, and gravity. All forces we experience in daily life are manifestations of these four.
For every action, there is an equal and opposite reaction. This means that any force exerted on a body is always paired with another force of equal magnitude and opposite direction exerted by that body.
Centripetal force is the net force that acts on an object to keep it moving in a circular path. It is always directed towards the center of the circle. Without it, the object would move in a straight line.
Friction is a force that opposes motion between surfaces in contact. While often seen as a nuisance, friction is essential for many activities, including walking and driving.
Hydraulic systems use an incompressible fluid to transmit force from one location to another. According to Pascal's principle, they can multiply force, allowing heavy loads to be lifted with a much smaller input force, as seen in car jacks and construction equipment.
The strong nuclear force is the most powerful of the four fundamental forces, but it only acts over extremely short distances. It's the force that binds protons and neutrons together in an atomic nucleus.
A rocket generates thrust by expelling mass (exhaust gas) at high velocity. In accordance with Newton's third law, the force on the ejected gas produces an equal and opposite force on the rocket, propelling it forward.
Tension is a pulling force transmitted through a string, cable, or chain. Compression is a pushing force that acts on an object. Both are fundamental forces in structural engineering.
In US engineering, a 'kip' is a unit of force equal to 1,000 pounds-force (lbf). The name comes from combining 'kilo' and 'pound'. It's often used for measuring large structural loads.
An airplane in flight is subject to four main forces: lift (upward), weight (downward), thrust (forward), and drag (backward). For level, constant-speed flight, these forces are in balance.
Surface tension is the tendency of liquid surfaces to shrink into the minimum surface area possible. It's a cohesive force that allows insects like water striders to walk on water.
This is a weak, short-range electrostatic force between uncharged molecules. It's the force that allows geckos to stick to walls; their feet have millions of tiny hairs that maximize surface contact and create a strong collective Van der Waals force.
The normal force is the perpendicular contact force exerted by a surface on an object resting on it. It's the force that prevents you from falling through the floor.
Impulse is the change in momentum of an object when a force is applied over a period of time (Impulse = Force × Time). This is why airbags in cars are effective; they increase the time over which the stopping force is applied, reducing the peak force on the passenger.
The Coriolis force is an inertial or 'fictitious' force that acts on objects in motion within a rotating frame of reference. On Earth, it deflects moving objects (like air currents and ocean currents) to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.