Cv / Kv Conversion - HVAC Calculator Toolbox

About this calculator This calculator converts between Cv (US) and Kv (metric) valve flow coefficients. Cv uses US gallons per minute at 1 PSI drop, while Kv uses cubic meters per hour at 1 bar drop. Use it when working with equipment or valve specifications from different regions, or when international projects require both coefficient standards.

Use when You need to convert valve coefficients between US and metric standards.

Formula Cv = Kv × 1.156 | Kv = Cv × 0.865

Variables

Cv US valve flow coefficientKv Metric valve flow coefficient

Cv → Kv

Kv → Cv

Conversion Direction

Enter the valve flow coefficient to convert

Kv —

What is the difference between Cv and Kv?

Cv and Kv are both valve flow coefficients that express a valve's flow capacity, but they use different units. Cv is the US standard, defined as the flow rate in US gallons per minute (GPM) of water at 60°F that produces a 1 PSI pressure drop. Kv is the international metric standard, defined as the flow rate in cubic meters per hour (m³/h) of water that produces a 1 bar pressure drop. The conversion factors are: Cv = Kv × 1.156, and Kv = Cv × 0.865. These factors derive from the unit conversions between GPM and m³/h, and between PSI and bar. In global HVAC projects, valve specifications may arrive in either standard depending on the manufacturer's origin. European valve manufacturers typically publish Kv values, while North American manufacturers publish Cv. Converting between the two ensures accurate valve selection regardless of which coefficient the manufacturer provides.

Related Calculators