This calculator allows you to convert from Earth's velocity to Mach (20°C, 1 atm) and in a reverse direction. To convert from Earth's velocity to Mach (20°C, 1 atm), enter the amount of Earth's velocity into the first input and to convert from Mach (20°C, 1 atm) to Earth's velocity, enter the amount of Mach (20°C, 1 atm) into the second input.