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## What is the formula for calculating rainfall?

If you normally measure annual rainfall in inches, **simply divide inches of rain by 12 to get annual rainfall in feet**. For example, folks in Phoenix, Arizona get about 7 inches of annual rainfall, so they would divide 7 by 12 to get 0.58 foot of annual rain.

## How much is 1 inch of rain in gallons?

Volume and weight

One inch of rain falling on 1 acre of ground is equal to about **27,154 gallons** and weighs about 113 tons. An inch of snow falling evenly on 1 acre of ground is equivalent to about 2,715 gallons of water.

## Can a 5 gallon bucket work as a rain gauge?

Most rain gauges for automatic weather stations are of the swinging bucket type, which must be installed in an accurately horizontal plane for correct operation.” The most accurate rain gage we have is a 5 **gallon bucket in the middle of the driveway turn around**.

## How do you calculate annual rainfall?

The **sum of rainfall in all the twelve months** = to the annual rainfall.

## How do you measure the amount of rain in a 5 gallon bucket?

**Here’s what you’ll need to do:**

- Measure the diameter of the bucket at the level of the rain. …
- Measure the diameter of the bucket at the bottom in the same way.
- Calculate the average of the two diameters.
- Divide by two to find the average radius.
- Find the average volume of rain = Depth x radius x radius x 3.14.

## How many gallons is 40 inches of rain?

Amount of Rain Falling on Your Property

If you own a single acre of property, that 40 inches of rain means your property receives **over 1 million gallons** of rain per year.

## How many raindrops are in a gallon?

The red circle is my eyeball guess at the average, which is a raindrop diameter of about 2mm. ² That gives us a radius of 1mm and a volume of 4 cubic millimeters. At a million cubic millimeters to the liter, that’s 250,000 drops per liter, or about **1 million drops per gallon**.