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. Simply take your roof s square footage and multiply by 62. 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. One inch of rain falling on 1000 sq ft of roof will deposit 623 gallons of water.

So for each inch of rainfall your roof could collect 1 246 gallons of rainwater. Rainwater can be collected from the roofs using the rain water harvesting method. 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. Take the dimensions of the footprint of your roof and convert them to inches.

1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall. How much will your roof be able to capture. The number of feet multiplied by 144 equals inches. Roof area ft2 x precipitation amount in x 0 623 amount collected gallons easy formula to remember.

The answer is about 623 gallons. For every 1 inch of rain and 1 000 square feet of roof you capture about 620 gallons of water. Rainwater collection calculation formulas and equations. When you look at the numbers it s surprising how much water you can collect every time it rains.

So each inch of rain on your roof will have 763 gallons of water going down your downspouts. You might even want to know how many baths you could get from your rainstorm. To calculate the runoff from any given rainfall. For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain.

Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water. The collectable rainwater from the roof can be calculated in gallons using this calculator based on the rainfall and area. For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches. An inch of rainfall on a square foot of surface area yields 623 gallons.

Multiply the area of your roof by the amount of rainfall you wish to calculate for. That is the theoretical best case outcome for this scenario. Consider your roof s size and harvesting capacity. 1 of rain on 1 000 sf roof will yield 623 gallons.

To find how much rain you can collect in an average rain year multiply this number by the average inches of rain. Roof area m2 x precipitation amount mm amount collected liters. If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year. Rainwater collection calculator in gallons.

This means that each square foot captures about 62 gallons per inch of rain.