Equivalent Duct Length Calculator

Convert duct fittings and components to equivalent straight duct length for total pressure drop calculations.

Total length of straight duct sections.
feet
Number of 90-degree elbows in the duct run.
qty
Number of 45-degree elbows in the duct run.
qty
Number of duct size transitions.
qty
Number of volume dampers (fully open).
qty
Number of branch takeoff connections.
qty

Results

90° Elbow Equivalent-feet
45° Elbow Equivalent-feet
Transition Equivalent-feet
Damper Equivalent-feet
Takeoff Equivalent-feet
Total Equivalent Length-feet
References: SMACNA HVAC Systems Duct Design; ASHRAE Fundamentals Chapter 21