Force Converter
Convert newtons, kilonewtons, pounds-force, kilograms-force and more
💡 Tip: Press Ctrl+D for dark mode, Ctrl+K to focus converter
💪 Force Converter
Convert between force units
Force Conversion Guide
Common Force Conversions
| From | To | Multiply by | Example |
|---|---|---|---|
| Newton | Pound-force | ÷ 4.448 | 100 N = 22.48 lbf |
| Pound-force | Newton | × 4.448 | 100 lbf = 444.8 N |
| Newton | Kilonewton | ÷ 1,000 | 1000 N = 1 kN |
| Kilonewton | Newton | × 1,000 | 1 kN = 1000 N |
| Newton | Kilogram-force | ÷ 9.807 | 100 N = 10.2 kgf |
| Kilogram-force | Newton | × 9.807 | 10 kgf = 98.07 N |
| Pound-force | Kilogram-force | × 0.4536 | 100 lbf = 45.36 kgf |
| Kip | Pound-force | × 1,000 | 1 kip = 1000 lbf |
| Dyne | Newton | ÷ 100,000 | 100,000 dyne = 1 N |
Understanding Force Units
Newton (N)
The newton is the SI unit of force, named after Sir Isaac Newton. One newton is the force required to accelerate 1 kilogram of mass at 1 meter per second squared.
Formula: 1 N = 1 kg⋅m/s²
Common uses: Physics calculations, engineering, scientific measurements
Kilonewton (kN)
A kilonewton equals 1,000 newtons. Commonly used in structural engineering and construction.
Example: A small car weighs about 10 kN (1,000 kg × 9.807 m/s²)
Pound-force (lbf)
Pound-force is the force exerted by gravity on a one-pound mass on Earth. It's commonly used in the United States.
Important: Don't confuse lbf (force) with lb (mass). 1 lb mass = 1 lbf force only on Earth.
Common uses: Bolts/fasteners, suspension systems, structural loads
Kilogram-force (kgf)
Kilogram-force is the force exerted by gravity on a 1-kilogram mass on Earth. Also called kilopond (kp).
Relation: 1 kgf = 9.807 N (because g ≈ 9.807 m/s²)
Common uses: Engineering in metric countries, torque specifications
Kip
A kip equals 1,000 pounds-force. Used in structural engineering in the US.
Example: A building column might support 50 kips (50,000 lbf)
Dyne
The dyne is a very small unit of force in the CGS system. 1 dyne = 10⁻⁵ N.
Use: Rarely used today, mostly in older scientific literature
Force Examples by Scale
| Object/Action | Approximate Force |
|---|---|
| Weight of a small apple | 1 N (100 g) |
| Weight of a 10 kg bag | 98 N (~22 lbf) |
| Firm handshake | 150-200 N (~34-45 lbf) |
| Weight of average person (70 kg) | 687 N (~154 lbf) |
| Force to break a chicken egg | 25-30 N (~6 lbf) |
| Car engine thrust | 3,000-8,000 N (0.7-1.8 kip) |
| Weight of small car (1000 kg) | 9,807 N (~10 kN) |
| Jet engine thrust | 100-500 kN (22-112 kip) |
| Space Shuttle main engine | 1.8 MN (400 kip) |
Force vs. Mass vs. Weight
Critical distinction:
- 💪 Force: Push or pull on an object (measured in N or lbf)
- ⚖️ Mass: Amount of matter in an object (measured in kg or lb)
- 🌍 Weight: Force of gravity on a mass (W = m × g)
- 📐 Relationship: Force = Mass × Acceleration (F = ma)
Example: A 10 kg mass:
- On Earth (g = 9.807 m/s²): Weight = 98.07 N = 22.05 lbf
- On Moon (g = 1.62 m/s²): Weight = 16.2 N = 3.64 lbf
- In space (g = 0): Weight = 0 N (but mass is still 10 kg!)
Newton's Laws of Motion
First Law (Inertia)
An object at rest stays at rest, and an object in motion stays in motion, unless acted upon by a force.
Second Law (F = ma)
The force on an object equals its mass times its acceleration: F = m × a
Example: To accelerate a 1000 kg car at 2 m/s², you need 2,000 N of force.
Third Law (Action-Reaction)
For every action, there is an equal and opposite reaction.
Example: When you push a wall with 100 N, the wall pushes back with 100 N.
Common Applications
Structural Engineering
- 🏗️ Building loads: Columns, beams, foundations (kN, kip)
- 🌉 Bridge design: Tension, compression forces (MN)
- 🏠 Roof loads: Snow, wind forces (N/m², kN)
Mechanical Engineering
- 🔩 Bolt tension: Tightening torque creates clamping force (N, lbf)
- ⚙️ Machine design: Forces on gears, shafts, bearings (kN)
- 🚗 Suspension systems: Spring forces, damper forces (N, lbf)
Physics & Science
- 🔬 Particle physics: Electromagnetic forces (pN, fN)
- 🧲 Magnetism: Attractive/repulsive forces (N)
- 🚀 Aerospace: Thrust, drag, lift forces (kN, MN)
Gravitational Acceleration Values
| Location | g (m/s²) | g (ft/s²) |
|---|---|---|
| Earth (standard) | 9.807 | 32.174 |
| Earth (equator) | 9.780 | 32.088 |
| Earth (poles) | 9.832 | 32.258 |
| Moon | 1.62 | 5.32 |
| Mars | 3.71 | 12.17 |
| Jupiter | 24.79 | 81.33 |
| Sun | 274 | 899 |
Frequently Asked Questions
What is the difference between force and mass?
Mass is the amount of matter in an object (kg or lb). Force is a push or pull (N or lbf). Weight is a force: W = m × g. A 10 kg mass always has 10 kg of mass, but its weight depends on gravity (98 N on Earth, 16 N on Moon).
How do I convert newtons to pounds-force?
Divide newtons by 4.448. For example: 100 N ÷ 4.448 = 22.48 lbf. To go the other way: multiply lbf by 4.448.
What is a newton in simple terms?
One newton is the force needed to accelerate 1 kilogram at 1 meter per second squared. It's roughly the weight of a small apple (100 grams). On Earth, 1 kg weighs 9.807 N.
What is the difference between lbf and lb?
lb (pound) is a unit of mass. lbf (pound-force) is a unit of force. On Earth, 1 lb mass exerts 1 lbf of force due to gravity. In space (no gravity), 1 lb mass has 0 lbf weight.
How much force is in a kilonewton?
1 kilonewton (kN) = 1,000 newtons = 224.8 pounds-force. It's roughly the weight of 100 kg (220 lb) on Earth.
What is kilogram-force (kgf)?
Kilogram-force is the force exerted by 1 kg mass in Earth's gravity. 1 kgf = 9.807 N = 2.205 lbf. It's used in some countries but being phased out in favor of newtons.
How do I calculate force?
Use Newton's Second Law: F = m × a where F is force (N), m is mass (kg), and a is acceleration (m/s²). Example: A 1500 kg car accelerating at 3 m/s² requires 4,500 N of force.
Force Conversion Formulas
Quick reference:
- Newton to lbf: N ÷ 4.448
- lbf to Newton: lbf × 4.448
- Newton to kgf: N ÷ 9.807
- kgf to Newton: kgf × 9.807
- kN to N: kN × 1,000
- N to kN: N ÷ 1,000
- Weight to Force: F = m × g (g = 9.807 m/s² on Earth)