How Many Gallons Of Rainwater My Roof

So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall.

How many gallons of rainwater my roof.

Take the dimensions of the footprint of your roof and convert them to inches. The collectable rainwater from the roof can be calculated in gallons using this calculator based on the rainfall and area. How much will your roof be able to capture. Roof area ft2 x precipitation amount in x 0 623 amount collected gallons easy formula to remember.

When you look at the numbers it s surprising how much water you can collect every time it rains. For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches. To calculate the runoff from any given rainfall. This means that each square foot captures about 62 gallons per inch of rain.

Roof area m2 x precipitation amount mm amount collected liters. So multiply 623 gallons by the number of surface square feet of your roof. So each inch of rain on your roof will have 763 gallons of water going down your downspouts. We ll fine tune it for the real world but let s first do a quick reality check before going any further.

That is the theoretical best case outcome for this scenario. Rainwater collection calculation formulas and equations. Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water. One inch of rain falling on 1000 sq ft of roof will deposit 623 gallons of water.

In our example it would be 623 x 2 000 which equals 1 246. Rainwater collection calculator in gallons. To find how much rain you can collect in an average rain year multiply this number by the average inches of rain. You might even want to know how many baths you could get from your rainstorm.

An inch of rainfall on a square foot of surface area yields 623 gallons. Consider your roof s size and harvesting capacity. 1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall. In the form below choose an area s and a rainfall amount to see how many gallons of water fell from the sky onto that area.

So for each inch of rainfall your roof could collect 1 246 gallons of rainwater. The number of feet multiplied by 144 equals inches. If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year. For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain.

To get an idea how much water the roof of your own house might yield use the rainfall harvest calculator above. Either way you would like to know how much rain has fallen how many gallons have come down from the skies onto your roof yard block or town. For every 1 inch of rain and 1 000 square feet of roof you capture about 620 gallons of water. The answer is about 623 gallons.

Multiply the area of your roof by the amount of rainfall you wish to calculate for.