# Hydrology Formulator

> Calculations on Water

Canonical page: [https://chrome-stats.com/d/id346512904](https://chrome-stats.com/d/id346512904)

## Overview

- **ID:** `id346512904`
- **Platform:** Apple
- **Type:** Apple app
- **Status:** Available
- **Publisher:** Historycentral.com
- **Category:** Productivity
- **Rating:** 5.00 / 5 (1 ratings)
- **Version:** 4.0.2
- **Last updated:** 2026-03-22
- **First published:** 2009-12-18
- **Size:** 18 MB
- **Data as of:** 2026-09-18
- **Store listing:** [Apple App Store](https://apps.apple.com/us/app/hydrology-formulator/id346512904)
- **Website:** [https://www.historycentral.com/Apps/Formulator/Hydrology.html](https://www.historycentral.com/Apps/Formulator/Hydrology.html)
- **Privacy policy:** [https://www.historycentral.com/privacy.html](https://www.historycentral.com/privacy.html)

## Description

HYDROLOGY FORMULATOR is the ultimate pocket reference for hydrologists, civil
  engineers, environmental scientists, and students. Packed with 1,000+
  formulas, calculators, and conversions, it covers everything from groundwater
  analysis to stormwater design — all in one powerful app.

  HYDROLOGY CALCULATORS

  Infiltration & Recharge — 17 Calculators
  - Porosity, Green-Ampt Infiltration, Horton Infiltration, Philip Infiltration,
   Holtan's Model, Hydraulic Conductivity, Groundwater Recharge, Mean Pore
  Velocity, Specific Discharge, Volumetric Water Content, and more

  Evaporation & Transpiration — 8 Calculators
  - Penman-Monteith ET0, Blaney-Criddle ET, Thornthwaite PET, Crop
  Evapotranspiration, Saturation Vapor Pressure, Evaporation Rate of Lake,
  Relative Humidity, Potential Evapotranspiration

  Open Channel Flow — 12 Calculators
  - Manning's Equation (SI & US), Chezy Equation, Froude Number, Hydraulic
  Radius, Hydraulic Jump, Critical Depth, Specific Energy, Reynolds Number, and
  more

  Pipe Flow — 7 Calculators
  - Darcy-Weisbach Equation, Hazen-Williams Velocity (SI & US), Reynolds Number,
   Water Hammer Pressure, Continuity Equation, Minor Head Loss

  Stormwater & Watershed — 9 Calculators
  - SCS Curve Number Runoff, SCS Peak Discharge, IDF Rainfall Intensity, Kirpich
   Time of Concentration, Gumbel Extreme Value, Detention Storage Volume,
  Composite Curve Number, and more

  Pumps & Water Supply — 7 Calculators
  - Total Dynamic Head, Water Horsepower, Brake Horsepower, NPSHa, Affinity Laws
   for Flow, Head, and Power

  Weirs & Orifices — 6 Calculators
  - Rectangular Weir (SI & US), V-Notch Weir, Broad-Crested Weir, Orifice Flow,
  Spillway Discharge

  Water Flow — 10 Calculators
  - Water Flow Rate, Velocity of Water, Volume of Water Flow, 90° V-Notch
  calculations, Pipe Total Diameter, and more

  Surface Runoff — 6 Calculators
  - Average Velocity, Runoff, Travel Time, Hourly Rate of Rainfall

  Groundwater — 7 Calculators
  - Darcy's Law, Thiem Equation, Cooper-Jacob Drawdown, Dupuit Well Flow, Radius
   of Influence, Storage Properties

  Soil Pollution — 5 Calculators
  - Groundwater Pore Velocity, Effective Diffusion, Hydrodynamic Dispersion,
  Aquifer Parameter, Variance of Pore Velocity

  River Pollution — 7 Calculators
  - River Oxygen Deficit, Critical Time & Distance for Oxygen Deficit,
  Re-Aeration Constants, Dissolved Oxygen, River Flow, Water Temperature

  Lake Pollution — 4 Calculators
  - Waste Entering, Equilibrium Concentration, Settling Loss Rate, Particle
  Deposition Rate

  Sediment Transport — 4 Calculators
  - Shields Parameter, Bed Shear Stress, Stokes' Law Settling Velocity,
  Meyer-Peter Müller Bedload

  Snow Hydrology — 2 Calculators
  - Snow Water Equivalent, Degree-Day Snowmelt

  Culvert Hydraulics — 2 Calculators
  - Culvert Headwater (Outlet Control), Culvert Outlet Control Head Loss

  Flood Routing
  - Muskingum Routing

  Water Balance
  - Water Balance Equation, Storage Continuity

  Plus: Area Formulas, Pollution Cleanup, and more

  CONVERSIONS & REFERENCE

  Hundreds of built-in conversions across 16 categories including:
  - Liquid Measures, Cubic Measures, Linear Measures, Square Measures
  - Flow Rates, Pressures, Horsepower, BTU, Watts, Power
  - Hydraulic Conversions, Sand-to-Volume, Ft-Lbs
  - 8 Temperature Scales (Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, Newton,
   Delisle, Rømer)
  - Metric Conversions and Fraction Conversions

  KEY FEATURES
  - Save and review past calculations
  - Switch between US (Imperial) and Metric units
  - Clean, intuitive interface designed for field and office use
  - Premium upgrade unlocks Groundwater, Pollution, Sediment Transport, Snow
  Hydrology, Culvert Hydraulics, and Flood Routing calculators

## Rankings

- #758,463 — Overall

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Source: [Chrome-Stats](https://chrome-stats.com/d/id346512904)