Pressure is defined as force distributed over an area. The basic relationship is:
When using mass mode, force is computed as: F = m × g, then pressure is calculated with the same P = F / A equation.
- Choose an input mode: force directly, or mass with gravity.
- Enter the force or mass, then select the appropriate unit.
- Enter the contact area and select its unit.
- Select a display unit and decimal precision for reporting.
- Press Calculate to view results above the form.
- Use Download CSV or Download PDF as needed.
| # | Force | Area | Pressure (kPa) | Typical context |
|---|---|---|---|---|
| 1 | 100 N | 0.01 m² | 10.0000 | Small press pad |
| 2 | 500 N | 0.02 m² | 25.0000 | Hand load spreader |
| 3 | 2 kN | 100 cm² | 200.0000 | Fixture contact patch |
| 4 | 150 lbf | 10 in² | 103.4214 | Clamp pressure estimate |
| 5 | 5 kN | 50 cm² | 1000.0000 | High load on small area |
1) What pressure from force and area means
Pressure describes how intensely a force is applied to a surface. The same force can feel gentle or damaging depending on contact area. In engineering, pressure is commonly expressed in pascals (Pa), where 1 Pa = 1 N/m². Practical work often uses kPa, MPa, bar, atm, or psi.
2) Core relationship and scaling behavior
The calculator uses P = F / A, which makes scaling easy to interpret. If force doubles and area stays the same, pressure doubles. If area doubles at the same force, pressure halves. This simple proportionality helps you sanity‑check results before reporting them.
3) Unit conversions and typical ranges
Conversions matter because pressure spans many orders of magnitude. Atmospheric pressure is about 101.325 kPa (1 atm). Many hydraulic systems operate in the 5–30 MPa range, while structural contact pressures may be tens to hundreds of kPa. For imperial reporting, 1 psi equals about 6.895 kPa.
4) Using mass to estimate force
When you select mass mode, the tool computes force as F = m × g. With standard gravity g = 9.80665 m/s², a 75 kg load produces about 735.5 N. This option is useful for estimating pressure from weights, fixtures, and lab loads where the applied force is gravitational.
5) Contact area: where most mistakes happen
Area must represent the true load‑bearing contact. Small errors in area create large pressure errors because area appears in the denominator. For example, 500 N on 0.02 m² gives 25 kPa, but the same 500 N on 0.002 m² gives 250 kPa. Measure contact patches carefully.
6) Handling high pressures and small areas
Very small areas can generate extreme pressures. A sharp tip or small seal contact can push results into MPa even for moderate forces. In such cases, choose an appropriate display unit (MPa or bar) and increase precision only if your input measurements justify it.
7) Data reporting and export workflow
Professional reports often require both inputs and converted outputs. The CSV export provides a quick way to paste values into spreadsheets, while the PDF export packages the same information in a clean, shareable format. Include the force source (direct vs mass × g) and area definition in your notes.
8) Practical use cases and quick checks
Use this calculator for clamp pressure estimates, pad loading, press fixtures, gasket seating, and simple contact studies. A quick check is comparing to 1 atm (101.325 kPa): if your result is much higher, the surface may require stronger materials or a larger contact area to reduce stress.
1) What units does the calculator support?
Force supports N, kN, and lbf. Area supports m², cm², mm², in², and ft². Results can be displayed in Pa, kPa, MPa, bar, atm, or psi, including automatic conversions.
2) Why does pressure increase so much when area is small?
Pressure is force divided by area. When area decreases, the same force is concentrated into a smaller region, so the ratio rises quickly. This is why sharp contacts and small pads produce high pressures.
3) How do I use mass mode correctly?
Enter mass in kilograms and confirm g in m/s². The calculator converts mass to force using F = m × g, then computes pressure using P = F / A. Use standard g unless local gravity is known.
4) What area should I enter for irregular shapes?
Use the effective load‑bearing contact area, not the visible outline. For irregular patches, estimate area from measured dimensions, a CAD projection, or a traced imprint. Document your method for repeatability.
5) Can this be used for fluid pressure?
Yes, if the force represents the net normal force acting on a surface and the area is the surface area. For hydrostatic pressure, force typically comes from fluid weight; other fluid effects may need additional models.
6) Why do my kPa and psi values not match expectations?
Check your input units first. A common mistake is mixing cm² with m² or in². Also verify the contact area is realistic. Small unit errors can change pressure by factors of 10,000 or more.
7) What precision should I select?
Choose precision based on measurement quality. If force and area are only known to two or three significant digits, displaying many decimals adds noise. Use 2–4 decimals for most engineering summaries.