Hydrology Calculators — Earth Science
Streamflow, runoff, infiltration, reservoir storage, and water-balance calculations. Each hydrology tool shows the governing equation so engineers and students can trace a result from rainfall input to discharge output.
All Hydrology & Water Resources Calculators
Calculate aquifer transmissivity with inputs, formulas, and instant results.
Calculate baseflow index with inputs, formulas, and instant results.
Calculate catchment runoff with inputs, formulas, and instant results.
Calculate drainage density with inputs, formulas, and instant results.
Calculate flow duration curve with inputs, formulas, and instant results.
Calculate flow resistance converter (n↔f) with inputs, formulas, and instant results.
Calculate groundwater flow velocity with inputs, formulas, and instant results.
Calculate groundwater recharge with inputs, formulas, and instant results.
Calculate hydraulic gradient (natural flow) with inputs, formulas, and instant results.
Calculate hydraulic radius with inputs, formulas, and instant results.
Calculate infiltration capacity decay (horton) with inputs, formulas, and instant results.
Calculate infiltration rate with inputs, formulas, and instant results.
Calculate manning’s equation (natural channel) with inputs, formulas, and instant results.
Calculate pan evaporation to lake evaporation with inputs, formulas, and instant results.
Calculate peak discharge (rational method) with inputs, formulas, and instant results.
Calculate pumping well drawdown (thiem theis) with inputs, formulas, and instant results.
Calculate recharge rate from water level decline with inputs, formulas, and instant results.
Calculate river discharge with inputs, formulas, and instant results.
Calculate runoff coefficient from land use with inputs, formulas, and instant results.
Calculate scs curve number with inputs, formulas, and instant results.
Calculate sediment transport rate with inputs, formulas, and instant results.
Calculate storage coefficient with inputs, formulas, and instant results.
Calculate stream power index with inputs, formulas, and instant results.
Calculate surface runoff coefficient with inputs, formulas, and instant results.
Calculate time of concentration (kirpich scs) with inputs, formulas, and instant results.
Calculate unit hydrograph s curve with inputs, formulas, and instant results.
Calculate water balance (catchment) with inputs, formulas, and instant results.
Calculate watershed area with inputs, formulas, and instant results.
Calculate watershed slope with inputs, formulas, and instant results.
About Hydrology & Water Resources Calculators
Streamflow, runoff, infiltration, reservoir storage, and water-balance calculations. Each hydrology tool shows the governing equation so engineers and students can trace a result from rainfall input to discharge output.
Whether you need to solve a one-time problem or verify your own calculations, these free tools cover the most common hydrology & water resources scenarios. All results are computed in your browser — no data is sent to any server.
What You Can Calculate
This section includes 29tools: Aquifer Transmissivity Calculator, Baseflow Index Calculator, Catchment Runoff Calculator, Drainage Density Calculator, Flow Duration Curve Calculator, Flow Resistance Converter Nf Calculator, Groundwater Flow Velocity Calculator, Groundwater Recharge Calculator, and 21 more. Each calculator is free to use with no signup required.