Rain Volume Calculator

Do you want to determine the volume of rainwater that falls on a specific area? Use this rain volume calculator, It is useful for managing water resources, planning irrigation, and understanding rainfall impact.

For calculation, just enter, length (in), width (in) and rain height (in) into the input fields of the tool. By pressing calculate button it will display rain volume (gallons) in the result field.

For advance level calculation, just enter area (sq in), rainfall (in) and runoff coefficient into the calculator. By pressing calculate button you will see effective rain volume (gallons) in result.

Rain Volume Calculator

Enter any 2 values to calculate the missing variable


This calculator can help you to easily and accurately calculate rainwater volume, which is important for several used like environmental and agricultural applications. The tool uses the dimensions of an area and the height of rainfall to calculate the volume of water in gallons.

How to Use the Calculator

To use the calculator, follow these steps:

  1. Enter the Length (L): Input the length of the area in inches.
  2. Enter the Width (W): Input the width of the area in inches.
  3. Enter the Rain Height (RH): Input the height of the rainfall in inches.
  4. Calculate the Rain Volume (RV): The calculator will use these inputs to compute the volume in gallons.

How to Calculate Rain Volume

The formula to calculate the rain volume is:

RV=L×W×RH231RV = \frac{L \times W \times RH}{231}



is the rain volume (gallons)


is the length of the area (inches)


is the width of the area (inches)


is the rain height (inches)

Example Calculation

Checkout some examples to see how the calculator works.

Example 1: Basic Calculation

  1. Length (L): 100 inches
  2. Width (W): 50 inches
  3. Rain Height (RH): 2 inches

Using the formula:

RV=L×W×RH231RV = \frac{L \times W \times RH}{231}

RV=100×50×2231RV = \frac{100 \times 50 \times 2}{231}

RV=10000231RV = \frac{10000}{231}

RV=43.29 gallonsRV = 43.29 \text{ gallons}

So, the rain volume is 43.29 gallons.

Example 2: Advanced Calculation

  1. Length (L): 200 inches
  2. Width (W): 150 inches
  3. Rain Height (RH): 3 inches

Using the formula:

RV=L×W×RH231RV = \frac{L \times W \times RH}{231}

RV=200×150×3231RV = \frac{200 \times 150 \times 3}{231}

RV=90000231RV = \frac{90000}{231}

RV=389.61 gallonsRV = 389.61 \text{ gallons}

So, the rain volume is 389.61 gallons.


Q1. Why would we need to compute the volume of rain?

Rain volume determination is helpful in water resource management, flood prediction, and agricultural planning.

Q2: Can this calculator be used for any area size?

Yes, this calculator would work for all dimensions—length in inches, width in inches, and rain height in inches—for any overall size.

Q3: What if I provide the wrong values as input?

Entering incorrect values will lead to either the wrong calculated results or will not be calculated. Be sure you have all the exact measurements to get the precise result.

I hope this calculator helped to determine the volume of rainfall in a specific area. This tool is helpful for environmental studies, agriculture, or urban planning. Please don’t hesitate to share your thoughts about the tool.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *