Kilogram-force (kgf) - Unit Information & Conversion
🔄 Quick Convert Kilogram-force
What is a Kilogram-force?
Kilogram-force (kgf) is the force exerted by one kilogram of mass under standard Earth gravity (9.80665 m/s²). Equal to 9.80665 newtons, it is widely used in engineering, automotive specifications, and mechanical systems.
History of the Kilogram-force
Originated from the meter-kilogram-second gravitational system (MKS). Historically called "kilopond" (kp) in some countries. Widely used in Europe, Asia, and engineering applications before SI standardization. Still common in automotive torque specs and mechanical engineering.
Quick Answer
What is Kilogram-force? A kilogram-force (kgf) is the force exerted by a one-kilogram mass in Earth's standard gravity. 1 kgf = 9.80665 newtons. Commonly used in mechanical engineering for torque specifications, hydraulic pressure, material strength testing, and automotive applications. Popular in European and Asian engineering contexts. Use our force converter to convert kilogram-force to newtons, pounds-force, and other units instantly.
Key Facts: Kilogram-force
| Property | Value |
|---|---|
| Symbol | kgf |
| Quantity | Force |
| System | Metric/SI Derived |
| Derived from | Newton |
| Category | Force |
| Standard Body | NIST / ISO |
Quick Comparison Table
| Kilogram-force | Newtons | Pounds-force | Context | Convert Now |
|---|---|---|---|---|
| 1 | 9.81 | 2.20 | Small weight (1 kg) | kgf to N → |
| 5 | 49.0 | 11.0 | Bag of flour | kgf to N → |
| 10 | 98.1 | 22.0 | Car floor jack rating | kgf to N → |
| 50 | 490 | 110 | Small person weight | kgf to N → |
| 70 | 686 | 154 | Average person weight | kgf to lbf → |
| 1,500 | 14,715 | 3,307 | Small car weight | kgf to kN → |
Definition
Kilogram-force (kgf) is the force exerted by one kilogram of mass under standard gravity (9.80665 m/s²).
Formula: 1 kgf = 1 kg × 9.80665 m/s²
Conversions:
- 1 kgf = 9.80665 N (newtons)
- 1 kgf = 0.00980665 kN (kilonewtons)
- 1 kgf = 2.204623 lbf (pounds-force)
- 1 kgf = 1,000 gf (gram-force)
- 1 kgf = 980,665 dynes
- 1 kgf = 35.274 ozf (ounce-force)
History
Kilogram-force emerged from the meter-kilogram-second gravitational system (MKS), which was used extensively in engineering before the adoption of SI units in the 1960s. In German-speaking countries and parts of Europe, it was called "kilopond" (kp), from the Latin word for weight. Despite the official adoption of the newton as the SI unit of force in 1960, kilogram-force remains prevalent in many engineering disciplines, particularly in automotive torque specifications, hydraulic systems, material testing, and construction equipment. Many Asian and European countries continue to use kgf in technical documentation and consumer products.
Common Uses
Automotive Engineering: Torque specifications (kgf·m), suspension loads, brake force.
Hydraulic Systems: Pressure ratings (kgf/cm² = 1 technical atmosphere).
Material Testing: Tensile strength, compression testing, hardness measurements.
Construction: Structural loads, lifting equipment capacity, crane ratings.
Consumer Products: Weight capacity labels, exercise equipment resistance.
Real-World Examples
Everyday Forces:
- Laptop computer weight: ~2 kgf
- Gallon of water: ~3.8 kgf
- Car tire weight: ~8-12 kgf
- Bicycle weight: ~10-15 kgf
- Average adult person: ~60-80 kgf
- Large dog: ~30-40 kgf
Automotive Applications:
- Wheel lug nut torque: 10-12 kgf·m (Nm)
- Engine head bolt torque: 8-15 kgf·m
- Brake caliper force: 500-1,500 kgf
- Clutch pedal force: 10-30 kgf
- Hood lift support: 5-20 kgf
- Small car weight: ~1,000-1,200 kgf
Industrial Equipment:
- Hydraulic press: 1,000-100,000 kgf
- Pneumatic cylinder: 100-10,000 kgf
- Vise grip force: 50-500 kgf
- Torque wrench range: 1-100 kgf·m
- Material testing machine: 1,000-50,000 kgf
- Crane lifting capacity: 500-20,000 kgf
Real-World Examples
Automotive Torque and Force Specifications
Critical mechanical measurements in kgf:
| Component | Specification (kgf·m) | In N·m | In lbf·ft | Purpose |
|---|---|---|---|---|
| Wheel lug nut | 10-12 | 98-118 | 72-87 | Tire security |
| Engine head bolt | 8-15 | 78-147 | 58-108 | Critical fastener |
| Oil drain plug | 2-4 | 20-39 | 15-29 | Pan security |
| Brake caliper | 2-3 | 20-29 | 15-22 | Brake pad secur |
| Suspension control arm | 5-10 | 49-98 | 36-72 | Alignment critical |
| Shock absorber | 3-7 | 29-69 | 21-51 | Suspension mount |
Hydraulic System Pressure Standards
Pressure expressed as kgf/cm² (technical atmosphere):
| Application | Pressure (kgf/cm²) | In Bar | In PSI | System Type |
|---|---|---|---|---|
| Power steering | 100-150 | 98-147 | 1,422-2,133 | Automotive |
| Wheel brake | 80-120 | 78-118 | 1,138-1,710 | Vehicle brakes |
| Hydraulic hoist | 200-250 | 196-245 | 2,845-3,557 | Heavy lifting |
| Punch press | 300-500 | 294-490 | 4,267-7,112 | Industrial |
| Industrial crane | 150-350 | 147-343 | 2,133-4,972 | Equipment |
Material Testing Force Ranges
Tensile and compression testing specifications:
| Test Type | Typical Range (kgf) | In Newtons | Equipment |
|---|---|---|---|
| Thread tensile | 10-100 | 98-980 | Small tester |
| Cable strength | 500-5,000 | 4,900-49,000 | Medium tester |
| Steel coupon | 1,000-50,000 | 9,800-490,000 | Large machine |
| Concrete cylinder | 10,000-100,000 | 98,000-980,000 | Heavy load cell |
Consumer Product Capacity Labels
Where kgf appears on equipment:
| Product | Capacity Rating (kgf) | In Pounds | Notes |
|---|---|---|---|
| Rope | 50-500 | 110-1,100 | Breaking strength |
| Carabiner | 20-40 | 44-88 | Climbing safety |
| Luggage strap | 10-20 | 22-44 | Travel security |
| Swing set | 100-150 | 220-330 | Weight limit |
| Exercise band | 5-30 | 11-66 | Resistance level |
How do I convert kilogram-force to newtons?
Formula: N = kgf × 9.80665 (approximately kgf × 9.81)
Examples:
- 1 kgf = 9.81 N
- 10 kgf = 98.1 N
- 50 kgf = 490.3 N
- 100 kgf = 980.7 N
Quick approximation: Multiply by 10 for rough estimates.
Kilogram-force to Newtons converter →
How many kilogram-force equal one newton?
1 newton = 0.10197 kilogram-force (approximately 0.102 kgf)
Quick conversions:
- 1 N = 0.102 kgf
- 10 N = 1.02 kgf
- 100 N = 10.2 kgf
- 1,000 N = 102 kgf
Rule of thumb: Divide newtons by 10 for approximate kgf.
Newtons to Kilogram-force converter →
What is the difference between kilogram and kilogram-force?
Kilogram (kg): Unit of MASS - measures amount of matter (SI base unit).
Kilogram-force (kgf): Unit of FORCE - measures weight or push/pull.
Relationship: On Earth at sea level, a 1 kg mass exerts 1 kgf of force due to gravity.
Critical distinction: On the Moon, a 1 kg mass still has 1 kg of mass but exerts only ~0.17 kgf of force due to lower gravity. In space (zero gravity), it exerts 0 kgf but still has 1 kg of mass.
Engineering note: Always use proper force units (N or kgf) in force calculations, not mass units.
Why is kilogram-force still used instead of newtons?
Historical momentum: Decades of engineering documentation use kgf.
Intuitive scale: For everyday objects, kgf matches familiar mass values.
Regional preference: Common in Europe, Asia, Latin America engineering.
Industry standards: Many automotive and hydraulic specs traditionally in kgf.
Convenient numbers: "10 kgf" is simpler than "98.1 N" in many contexts.
Transition period: Many countries gradually shifting to SI units, but legacy equipment and documentation persist.
Kilogram-force Conversion Formulas
To Newton:
To Millinewton:
To Kilonewton:
To Meganewton:
To Dyne:
To Pound-force:
To Gram-force:
To Metric Ton-force:
To US Ton-force:
To UK Ton-force:
To Poundal:
To Ounce-force:
To Kip:
Convert Kilogram-force
Need to convert Kilogram-force to other force units? Use our conversion tool.
Kilogram-force Quick Info
Related Force Units
Popular Conversions
- Kilogram-force to NewtonConvert →1 kgf = 9.80665 N
- Kilogram-force to MillinewtonConvert →1 kgf = 9806.65 mN
- Kilogram-force to KilonewtonConvert →1 kgf = 0.009807 kN
- Kilogram-force to MeganewtonConvert →1 kgf = 0.00001 MN
- Kilogram-force to DyneConvert →1 kgf = 980665 dyn
- Kilogram-force to Pound-forceConvert →1 kgf = 2.204623 lbf