Unit definitions

Pascal

The pascal is the SI unit of pressure. It is defined as one newton per square meter.

Kilopascal

One kilopascal equals $10^3$ pascals.

Millimeters of mercury

mmHg is the global standard for measuring blood pressure. $P = \rho \cdot g \cdot h$ can be used to calculate the hydrostatic pressure exerted by a fluid. $$P = \rho \cdot g \cdot h$$ $\rho \approx 13\,595.1\ \text{kg/m}^3$ at $0^\circ\text{C}$ $$g = 9.806\,65\ \text{m/s}^2$$ $$h = 0.001\ \text{m}$$ $$1\ \text{mmHg} \approx 133.322\ \text{Pa}$$

Inches of mercury

Pressure in inHg can be calculated using $P = \rho \cdot g \cdot h$. $$1\ \text{inHg} \approx 3\,386.39\ \text{Pa}$$

Pounds per square inch

One psi equals one pound (avoirdupois) force applied to an area of one square inch. Pound force can be derived as follows. $$F = m \cdot a$$ $$a = g = 9.806\,65\ \text{m/s}^2$$ $$m = 1\ \text{lb}$$ $$1\ \text{lb} = 0.453\,592\,37\ \text{kg}$$ $$1\ \text{lbf} = 0.453\,592\,37 \ \text{kg} \times 9.806\,65 \ \text{m/s}^2$$ $$1\ \text{lbf} \approx 4.448\,222 \ \text{N}$$ After dividing by the area of one square inch, we get the following. $$1\ \text{psi} = \frac{1\ \text{lbf}}{1\ \text{in}^2}$$ $$1\ \text{in}^2 = 0.000\,645\,16\ \text{m}^2$$ $$1\ \text{psi} \approx 6\,894.76\ \text{Pa}$$

Convert Pascal to other Pressure units

Convert Pascal to other Pressure units

Pascal [Pa]	Other unit
1	0.000145 Pounds per square inch [psi]
1	0.007501 Millimeters of mercury [mmHg]
1	0.000295 Inches of mercury [inHg]
1	0.001 Kilopascal [kPa]