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Pressure Calculator

Pressure calculator

Solve pressure, force, or area with synchronized engineering units.

InputsPressureDifferential • paLive

Pressure

200 Pa

100 N ÷ 0.5 m²

Live

P = F / A

Differential

Kilopascal

0.2 kPa

PSI

0.02901 psi

Bar

0.002 bar

P = F / A gives applied or differential pressure; it is not automatically absolute pressure.

Steps and pressure context
  1. Convert force to 100 N.
  2. Convert area to 0.5 m².
  3. Divide force by area: 100 ÷ 0.5 = 200 Pa.

Gauge vs absolute

Net force on a piston depends on pressure difference across it. Absolute pressure equals gauge pressure plus ambient pressure.

Formula
P = F / A; F = P x A; A = F / P
F = P A
A = \frac{F}{P}

Symbol legend

Symbol Meaning Unit Copy
P Pressure Pa
F Applied normal force N
A Area m^2
  • Pressure equals normal force divided by the effective area carrying that force.
  • Force equals pressure difference multiplied by effective area.
  • Area equals force divided by pressure; one pascal is exactly one newton per square meter.
Example

Worked example: 100 N on 0.5 m²

  1. 1 Force = 100 N
  2. 2 Effective area = 0.5 m²
  3. 3 P = F / A = 100 / 0.5 = 200 Pa

Pressure is 200 Pa.

How
  1. Choose Pressure, Force, or Area as the unknown.
  2. Enter the two known magnitudes and select a unit for each.
  3. Choose the answer unit and read the live equation, equivalents, and conversion steps.
  4. Open pressure context when a gauge reading must be related to ambient and absolute pressure.
Avoid
  • Using total surface area instead of the effective area carrying the normal force.
  • Treating absolute pressure as the pressure difference across a piston or surface.
  • Using zero or negative area, which is invalid in this magnitude model.
  • Changing a unit label without converting the associated numeric value.
FAQ
What is the SI unit of pressure?

The SI unit is pascal, equal to one newton per square meter.

What pressure does P = F/A represent?

It represents applied or differential pressure over an effective area. For a piston, net force depends on the pressure difference across the piston, not one side absolute pressure alone.

How do gauge and absolute pressure relate?

Absolute pressure equals gauge pressure plus ambient absolute pressure. Standard atmosphere is 101.325 kPa, but actual ambient pressure varies.

Does changing units preserve the physical value?

Yes. Unit changes on known inputs convert the numeric value so the same physical force, area, or pressure is preserved.

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