Time of Concentration & Travel Time

• Travel Time / Time of Concentration Calculator
• Kirpich’s Time of Concentration Calculator
• Kerby’s Time of Concentration Calculator
• FAA Time of Concentration Calculator
• NRCS Travel Time Calculator
• Overland Flow Time of Concentration Calculator

Hydrograph & Discharge Calculators

• Triangle Hydrograph Method Calculator
• Double-End Area Method Calculator
• Hydrograph Method Peak Discharge Calculator
• Reduced Peak Discharge Calculator
• Stormwater Peak Discharge Calculator

Underdrain Calculators

• Required Underdrain Lateral Spacing Calculator
• Underdrain System Discharge Calculator
• Area Served by Underdrain Laterals Calculator

Recovery Calculators

• Vertical Unsaturated Recovery Calculator
• Horizontal Saturated Recovery Calculator

Storage & Runoff Calculators

• Stage Storage Depth Calculator
• Pond Storage Volume Calculator
• Stormwater Runoff Volume Calculator
• Detention Storage Volume Calculator
• Rational Formula Runoff Depth Calculator
• Rainfall Intensity Calculator
• Weighted Curve Number Calculator for a Basin
• Composite Curve Number Calculator with Unconnected Impervious Area
• Composite Curve Number Calculator

Friction Loss & Pipe Calculators

• Partial Flow Pipe Expansion Friction Loss Calculator
• Partial Flow Pipe Contraction Friction Loss Calculator
• Thru Manhole Friction Loss Calculator
• Pipe Expansion Friction Loss Calculator
• Pipe Contraction Friction Loss Calculator
• Friction Loss in Bend Calculator
• Required Pipe Diameter Calculator
• Pipe Load from Distributed Load Calculator
• Pipe Load Calculator
• Culvert Outlet Velocity Calculator

Channel & Velocity Calculators

• Channel Flow (Q) Calculator
• Channel Velocity Calculator
• Average Velocity Calculator
• Froude Number Calculator

Miscellaneous Calculators

• FHWA Orifice Outlet Control Required Area Calculator
• Channel Bend Elevation Difference Calculator