How Much Rain Falls On Your Roof A Year

Use square kilometers for large areas.

How much rain falls on your roof a year.

1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall. You have to admit that whether you re in a drought situation or not it s hard to pass up that much of a free thing. Take the dimensions of the footprint of your roof and convert them to inches. Keep in mind most rain falls over 2 3 months of a year.

Multiply the area of your roof by the total obtained in step 2 as outlined in the following equation. Let s take a look at one more example to see how much of a difference collecting rainwater can make if you live in boston massachusetts which gets an average of 42 53 inches of rain per year and you live in a house with 1 000 square feet of roof space 1 000 x 0 6 x 42 53 25 518 gallons of water collected each year in boston ma. For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain. Select one or more methods to choose the size of your area.

It isn t uncommon for an area to collect up to 350mm of rain in just one month even in rural areas. If your average rainfall was 25 inches year your annual collection potential is 1 120 x 25 28 000 gallons year. The number of feet multiplied by 144 equals inches. So a 50 x 20 roof is 600 x 240.

To calculate the runoff from any given rainfall. For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches. Multiply the area of your roof by the amount of rainfall you wish to calculate for. F x p a 4 estimate the rainfall per event in your area r by dividing the annual precipitation rate by the number of rain days per year.

Use meters for areas such as your roof or yard. The answer is about 623 gallons. I think you ll be surprised about much rain really does fall during a rainstorm. You can enter numbers into any or all of the boxes below.

An average suburban roof of 200m 2 with such a rain fall can potentially harvest 100 000l of rainwater 200m 2 500mm 100 000l. If you get about 10 inches of rain over the course of the spring and summer an average 1 360 square foot roof would yield 8 160 gallons of rainwater.