Rainwater Off Roof Calculator

1 500 x 144 216 000 multiply those 216 000 square inches by the rainfall.

Rainwater off roof calculator.

Rainwater collection calculator in gallons rainwater can be collected from the roofs using the rain water harvesting method. Use the zoom tool in the lower right hand corner of the map to get closer so you can see draw on your roof. To calculate the runoff from any given rainfall. Column 1 column 1 column 1 column 1.

The resulting figure represents the surface area of your roof in square metres. Use our metric system version. The collectable rainwater from the roof can be calculated in gallons using this calculator based on the rainfall and area. Use our water catchment and water usage calculators below to make your selection easier.

Water catchment calculator how much rainwater can you harvest. Factors such as evaporation wetting and soaking into the ground are not considered here. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. Annual rainfall in millimetres x roof surface area in square metres roof catchment capacity.

Take the dimensions of the footprint of your roof and convert them to inches. This capacity can be calculated using the following formula. Code to add this calci to your website. For example if you have a roof that measures 1 500 square feet that equals 216 000 square inches.

Although this calculation is simple in principle the units can make it a headache. 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. Rain barrel supplies list. Rainfall calculator english units how much water falls during a storm.

Gutters and a downspout. Need help selecting which tank is right for you. The area measurement will appear right above the map. Roughly speaking 1 millimetre of rain over 1 square metre of roof equals 1 litre of water.

Once you have the square footage number enter it into the rainwater collection calculator above. Then click on the outer points of your roof and a polygon will instantly be created. Multiply the area of your roof by the amount of rainfall you wish to calculate for. Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water.

If you don t already have rain gutters on your house this one time investment is the biggest cost you ll face. 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. To work out the surface area simply multiply the length in metres by width for square or rectangular roofs.