Valve & Flow Sizing

Valve and flow sizing calculators help HVAC engineers select and verify control valves and hydronic system components. This collection includes tools for calculating valve Cv and Kv coefficients, determining flow rates through valves at known pressure drops, converting between GPM and pressure loss, and sizing valves for proper authority in hydronic circuits. Correct valve sizing is critical to system controllability — an oversized valve hunts and oscillates, while an undersized valve cannot deliver design flow. These calculators apply standard flow coefficient formulas used by valve manufacturers worldwide so results match published catalog data. Use them during design to specify the right valve for each application, or during commissioning to confirm that installed valves are providing the expected flow characteristics and pressure drops.