kg/cm² to psi Converter
Pressure on imported equipment is often written as kg/cm², while U.S. manuals and gauges usually use psi. This calculator converts the practical pressure unit kilogram-force per square centimeter to pounds per square inch, and it also converts psi back to kgf/cm². The default example is 7 kgf/cm², which the form reports as 99.5634 psi.
The page is written for tire, pump, hydraulic, compressor, and industrial maintenance work, not for pure mass conversion. A kilogram by itself is mass; pressure requires force divided by area. In older gauge labels the shorter notation kg/cm² usually means kgf/cm², where kilogram-force is the force associated with one kilogram under standard gravity. That convention is why the form labels results with kgf/cm² even though the slug and title use the search phrase kg/cm².
For related pressure scales, compare this result with the kPa to psi conversion, the bar to psi converter, and the broader pressure calculator. If your source is a materials stress value rather than a gauge, the MPa to psi conversion may be a better match.
What kgf/cm² means
Kilogram-force per square centimeter is a force-per-area unit. One kilogram-force spread across one square centimeter creates one kgf/cm². It is closely related to the technical atmosphere, a non-SI pressure unit historically used in engineering. Psi uses the same force-per-area idea but with pound-force over square inches.
| Unit | Expanded meaning | Typical domain |
|---|---|---|
| kgf/cm² | kilogram-force per square centimeter | industrial gauges, tires, pumps |
| psi | pound-force per square inch | U.S. tires, compressors, hydraulics |
| kPa | kilopascal | SI-style equipment labels |
| bar | 100000 pascals | compressors and process gauges |
| MPa | megapascal | materials stress and high pressure |
The calculator uses a fixed factor:
Because the form is a two-way converter, it multiplies by that factor in one direction and divides by it in the other.
Formula used by the calculator
For kgf/cm² to psi:
For psi to kgf/cm²:
The result also displays the conversion factor. The factor is derived transparently from 1 kgf/cm² = 98,066.5 Pa and 1 psi = 6,894.757293168361 Pa; the form carries the displayed 16-digit factor in both directions. Values below zero are invalid because the input is meant for ordinary pressure settings, not signed vacuum gauges.
Conversion example matching the default
With the direction left on kgf/cm² to psi and the pressure set to 7, the form calculates:
The primary result is 99.5634 psi. The items beneath it show 7 kgf/cm² and the rounded factor 14.2233 psi per kgf/cm². The note states the full factor used for the default direction.
Switch the direction to psi to kgf/cm² and enter 100. The calculator divides instead:
The primary value becomes 7.030696 kgf/cm², while the supporting row keeps the entered 100 psi visible. That reverse example helps when a U.S. gauge needs to be matched to a metric-force service manual.
Reference table
| kgf/cm² | psi from the calculator | Example context |
|---|---|---|
| 1 | 14.2233 | low pressure reference |
| 2 | 28.4466 | light pneumatic setting |
| 3.6 | 51.2039 | tire-style range in some charts |
| 7 | 99.5634 | default hydraulic or compressor example |
| 10 | 142.2330 | industrial gauge reading |
| 20 | 284.4660 | higher hydraulic pressure |
Round the table values to match the gauge you are actually setting. A tire placard may specify a neat psi value even if the kgf/cm² equivalent is not neat, and a service manual may do the reverse.
Tire and industrial usage notes
For tires, kgf/cm² and psi are gauge pressure scales. If the placard says 2.4 kgf/cm², converting to psi gives about 34.14 psi, but the setting should still be checked cold if the vehicle manufacturer requires cold inflation pressure. Unit conversion does not adjust for temperature, altitude, or load.
For hydraulics and pumps, verify whether the rating is maximum working pressure, test pressure, or relief-valve setting. Converting a number accurately is not the same as confirming that a hose, seal, or fitting is safe. If a part is rated in bar or MPa rather than kgf/cm², use a direct converter before comparing.
For materials stress, kgf/cm² can appear in older specifications, but MPa is usually the modern SI unit. Stress and pressure share dimensions, yet the engineering meaning differs: pressure acts on fluids or surfaces, while stress describes internal force per area inside a material. Keep the domain attached to the number.
Common mistakes
- Treating kg/cm² as kilograms of mass per area. The calculator uses kilogram-force per square centimeter.
- Rounding the factor to 14 when setting equipment. That shortcut is too coarse for many pressure settings.
- Mixing gauge and absolute pressure. Tire and hydraulic values are usually gauge readings.
- Converting a force value without area. A value in kgf alone is not pressure.
- Assuming a converted value is safer than the original rating. Always respect the manufacturer’s pressure limit.
Sources
- NIST, Definitions of the SI base units and SI prefixes — SI units and prefixes used to distinguish force, area, and pressure.
- BIPM, The International System of Units, 9th edition — pascal and coherent derived-unit background.
- NIST, Handbook 44, Appendix C — exact international inch and pound definitions used to derive psi.
- NIST, standard acceleration of gravity — exact standard-gravity value used for kilogram-force and pound-force.