How Much Rain Falls On Your Roof A Year

You can enter numbers into any or all of the boxes below.

How much rain falls on your roof a year. To find how much rain you can collect in an average rain year multiply this number by the average inches of rain. 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. Take the dimensions of the footprint of your roof and convert them to 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.

Use meters for areas such as your roof or yard. 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. The answer is about 623 gallons.

Multiply the area of your roof by the total obtained in step 2 as outlined in the following equation. To calculate the runoff from any given rainfall. I think you ll be surprised about much rain really does fall during a rainstorm. 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. Keep in mind most rain falls over 2 3 months of a year. So a 50 x 20 roof is 600 x 240. The number of feet multiplied by 144 equals inches.

For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches. 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. For example on a 2 000 square foot roof you can collect 2 000 x 0 56 1 120 gallons inch of rain. 1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall.

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