\begin{aligned} 1\,\mathsf{m^3} &= 1000\,\text{L} \quad (\textsf{litres}) \\ 1\,\mathsf{kg\cdot m/s^2} &= 1\,\text{N} \quad (\textsf{Newton}) \\ 1\,\mathsf{N/m^2} &= 1\,\text{Pa} \quad (\textsf{Pascal}) \\ 1\,\mathsf{kN/m^2} &= 1\,\text{kPa} \quad (\textsf{kilopascal}) \\ 1\,\mathsf{N/mm^2} &= 1\,\text{MPa} \quad (\textsf{megapascal}) \\ \textsf{Pressure:} \quad P &= \frac{F}{A} \quad \left(= \frac{\textsf{force}}{\textsf{area}}\right) \\ \textsf{Density:} \quad \rho \textsf{ (rho)} &= \frac{m}{V} \quad \left(= \frac{\textsf{mass}}{\textsf{volume}}\right) \\ \textsf{Specific Weight:} \quad \gamma \textsf{ (gamma)} &= \frac{w}{V} \quad \left(= \frac{\textsf{weight}}{\textsf{volume}}\right) \\ \gamma &= \rho{}g \\ \textsf{Specific Gravity:} \quad \textsf{sg} &= \frac{\rho_s}{\rho_{w@4\degree\! C}} \quad \small\left(= \frac{\textsf{density of substance}}{\textsf{density of water at } 4\degree\! C}\right) \\ &= \frac{\gamma_s}{\gamma_{w@4\degree\! C}} \quad \small\left(= \frac{\textsf{spec.wt of substance}}{\textsf{spec.wt of water at } 4\degree\! C}\right) \\ p_{abs} &= p_{atm} + p_{gauge} \\ \Delta p &= \gamma h \end{aligned}