Rainwater Off Roof Calculator

Roughly speaking 1 millimetre of rain over 1 square metre of roof equals 1 litre of water.

Rainwater off roof calculator.

Although this calculation is simple in principle the units can make it a headache. Factors such as evaporation wetting and soaking into the ground are not considered here. Use our metric system version. The resulting figure represents the surface area of your roof in square metres.

Need help selecting which tank is right for you. Column 1 column 1 column 1 column 1. Gutters and a downspout. The number of feet multiplied by 144 equals inches.

The area measurement will appear right above the map. For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches. The collectable rainwater from the roof can be calculated in gallons using this calculator based on the rainfall and area. 1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall.

So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. Rain barrel supplies list. The catchment areais multiplied by the depth of rain that falls on it to give the total volumeof waterproduced. Multiply the area of your roof by the amount of rainfall you wish to calculate for.

Since rainwater is collected from rooftops you will need to work out the total surface area of roof s that will be used to catch rainwater. Use our water catchment and water usage calculators below to make your selection easier. To get an idea how much water the roof of your own house might yield use the rainfall harvest calculator above. To work out the surface area simply multiply the length in metres by width for square or rectangular roofs.

Water catchment calculator how much rainwater can you harvest. It is the middle of july in georgia and both you and your tomatoes are wilting in your yard both looking to the sky and hoping for rain. Code to add this calci to your website. Use the zoom tool in the lower right hand corner of the map to get closer so you can see draw on your roof.

Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water. Once you have the square footage number enter it into the rainwater collection calculator above. To calculate the runoff from any given rainfall. If you don t already have rain gutters on your house this one time investment is the biggest cost you ll face.

Then click on the outer points of your roof and a polygon will instantly be created. Rainwater collection calculator in gallons rainwater can be collected from the roofs using the rain water harvesting method. Annual rainfall in millimetres x roof surface area in square metres roof catchment capacity.