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.

The collectable rainwater from the roof can be calculated in gallons using this calculator based on the rainfall and area. To calculate the runoff from any given 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 multiply 623 gallons by the number of surface square feet of your roof.

In our example it would be 623 x 2 000 which equals 1 246. You might even want to know how many baths you could get from your rainstorm. Rainwater can be collected from the roofs using the rain water harvesting method. How much will your roof be able to capture.

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. Rainwater collection calculation formulas and equations. Roof area ft2 x precipitation amount in x 0 623 amount collected gallons easy formula to remember. 1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall.

1 of rain on 1 000 sf roof will yield 623 gallons. Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water. So each inch of rain on your roof will have 763 gallons of water going down your downspouts. The answer is about 623 gallons.

Multiply the area of your roof by the amount of rainfall you wish to calculate for. Take the dimensions of the footprint of your roof and convert them to inches. Roof area m2 x precipitation amount mm amount collected liters. For every 1 inch of rain and 1 000 square feet of roof you capture about 620 gallons of water.

When you look at the numbers it s surprising how much water you can collect every time it rains. Rainwater collection calculator in gallons. We ll fine tune it for the real world but let s first do a quick reality check before going any further. One inch of rain falling on 1000 sq ft of roof will deposit 623 gallons of water.

Consider your roof s size and harvesting capacity. The number of feet multiplied by 144 equals inches. This means that each square foot captures about 62 gallons per inch of rain. If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year.

To get an idea how much water the roof of your own house might yield use the rainfall harvest calculator above. That is the theoretical best case outcome for this scenario. For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain. An inch of rainfall on a square foot of surface area yields 623 gallons.

For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches.