How Much Rain Falls On Your Roof A Year

Use meters for areas such as your roof or yard.

How much rain falls on your roof a year. So a 50 x 20 roof is 600 x 240. An average suburban roof of 200m 2 with such a rain fall can potentially harvest 100 000l of rainwater 200m 2 500mm 100 000l. 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. Select one or more methods to choose the size of your area.

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

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. 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. Or maybe a low pressure cell has been napping overhead and your arm is hurting from holding that umbrella while you watch your basement fill up with water. Multiply the area of your roof by the total obtained in step 2 as outlined in the following equation.

Take the dimensions of the footprint of your roof and convert them to inches. The answer is about 623 gallons. For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain. You can enter numbers into any or all of the boxes below.

To calculate the runoff from any given rainfall. 1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall. Multiply the area of your roof by the amount of rainfall you wish to calculate for. Use square kilometers for large areas.

Keep in mind most rain falls over 2 3 months of a year. 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.