Fire Hose Friction Loss

Friction loss through a hose lay, from its diameter, length, and flow.

Example

You enter

You get

Details, formula, and sources

CQ^2L formula by hose diameter, length, GPM.

Friction loss FL = C × Q² × L per 100 ft of hose. C and L per hose diameter from NFA training tables (1.75 in, 2.5 in, 3 in, 4 in, 5 in, etc.).

National Fire Academy hose-hydraulics training materials (U.S. government, public domain).

Free at usfa.fema.gov/training.

Estimate. AHJ and licensed fire protection engineer govern.

Field names used by the API: hose_diameter, gpm, length_ft, friction_loss_psi