Kilogram-force to Kip-force
kgf
kipf
Conversion History
| Conversion | Reuse | Delete |
|---|---|---|
| No conversion history to show. | ||
Quick Reference Table (Kilogram-force to Kip-force)
| Kilogram-force (kgf) | Kip-force (kipf) |
|---|---|
| 1 | 0.00220462262185146059 |
| 5 | 0.01102311310925730293 |
| 10 | 0.02204622621851460585 |
| 70 | 0.15432358352960224097 |
| 100 | 0.22046226218514605853 |
| 500 | 1.10231131092573029263 |
| 1,000 | 2.20462262185146058525 |
About Kilogram-force (kgf)
The kilogram-force (kgf), also called kilopond (kp), is the gravitational force on a 1-kilogram mass under standard gravity, equal to exactly 9.80665 N. It is widely used in mechanical engineering, hydraulics, and everyday language in countries that have not fully adopted SI force units. Lifting capacity of hoists, safe working loads of chains and slings, and tensile strengths of ropes and cables are often quoted in kgf or tonnes-force in European and Asian manufacturing contexts. Spring balances and older force gauges are calibrated in kgf.
A 70 kg person weighs approximately 70 kgf. A small hydraulic jack rated at 2 tonnes supports 2,000 kgf.
About Kip-force (kipf)
The kip-force (kipf or kip) equals exactly 1,000 pound-force, approximately 4,448 N. It is the standard force unit in American structural and civil engineering, used in the AISC steel construction manual, ACI concrete codes, and AASHTO bridge design specifications. Column axial loads, beam reactions, foundation pressures, and connection capacities in US structural engineering are invariably reported in kips. The unit's name is a portmanteau of "kilo" and "pound". Stress is then expressed as ksi (kips per square inch), paralleling the SI use of megapascals.
A typical steel wide-flange column in a multi-story building carries 200–1,000 kips of axial load. A major bridge pier reaction may exceed 10,000 kips.
Etymology: Portmanteau of "kilo" and "pound". Emerged in American structural engineering practice during the early 20th century as building structures grew large enough that pound-force values became unwieldy.
Kilogram-force – Frequently Asked Questions
Why do some countries still use kilogram-force instead of newtons?
Many countries in Europe and Asia adopted kgf in engineering and industry before SI became dominant. Crane ratings, hydraulic press capacities, and elevator load limits were standardized in kgf and remain labelled that way on existing equipment. Rewriting decades of documentation and re-stamping machinery is costly, so kgf persists in practice even where SI is officially mandated.
How do you convert kilogram-force to newtons?
Multiply kilogram-force by 9.80665 to get newtons. So 1 kgf = 9.80665 N, and 100 kgf = 980.665 N. For quick estimates, multiply by 9.81 or roughly 10. This conversion factor is simply the standard acceleration due to gravity in m/s².
What is the difference between kilogram-force and kilopond?
They are the same unit. Kilopond (kp) was the name used in Germany, Scandinavia, and other European countries, while kilogram-force (kgf) is the internationally recognized term. Both equal the gravitational force on 1 kg at standard gravity. ISO 80000-4 deprecates both in favor of the newton, but kgf remains common in Asian and European industrial contexts.
Why is kilogram-force problematic in engineering calculations?
Using kgf conflates mass and force, leading to errors when gravity varies or when applying F = ma. Engineers must insert a gravitational constant (gₙ = 9.80665 m/s²) to convert between mass and force, which SI avoids by using separate units — kilograms for mass and newtons for force. Mistakes in this conversion have caused real-world structural miscalculations.
What are typical kilogram-force values in everyday life?
A 70 kg adult weighs about 70 kgf. A firm handshake exerts roughly 10–15 kgf. A bicycle tire inflated to 6 bar exerts about 4.5 kgf per cm² on the rim. These values feel intuitive because they numerically match familiar masses, which is precisely why kgf remains popular in non-technical contexts despite SI deprecation.
Kip-force – Frequently Asked Questions
What is a kip in structural engineering?
A kip (or kip-force) equals 1,000 pound-force, roughly 4,448 N or 4.45 kN. It is the everyday force unit in US structural engineering, keeping beam reactions and column loads in manageable two- to four-digit numbers instead of tens of thousands of pounds. The name is a portmanteau of "kilo" and "pound".
Why do American engineers use kips instead of kilonewtons?
US building codes (AISC, ACI, AASHTO) were written in imperial units decades before SI adoption. Kips pair naturally with ksi (kips per square inch) for stress, matching the imperial measurement ecosystem. Switching to kilonewtons would require rewriting entire code libraries, recalibrating testing equipment, and retraining a generation of practitioners.
How many kips of wind load does a skyscraper experience during a hurricane?
A 50-story tower with a 200 × 100 ft footprint in a Category 3 hurricane (130 mph winds) might see a total wind base shear of 3,000–5,000 kips and an overturning moment of 500,000–1,000,000 kip-ft. The load varies dramatically with height — wind pressure at the top floor can be 3× the pressure at ground level due to the atmospheric boundary layer profile. Structural engineers design the lateral system (moment frames, braced cores) to resist these loads with a safety factor of ~1.6.
What is ksi and how does it relate to kips?
Ksi stands for kips per square inch — it is the imperial unit of stress equivalent to 1,000 psi. A36 structural steel has a yield strength of 36 ksi, meaning 36 kips of force per square inch of cross-section. Ksi parallels the SI unit megapascal (MPa); 1 ksi ≈ 6.895 MPa.
What are typical kip values for building column loads?
A steel wide-flange column in a mid-rise office building carries roughly 200–600 kips per floor of tributary load. A ground-floor column in a 10-story building might see 2,000–4,000 kips total. Major bridge piers can exceed 10,000 kips. These ranges help engineers quickly sanity-check calculations during preliminary design.