Solar Calculator is an application that calculates the 24 hour energy requirement of a household and based upon that calculates the number of Solar Panels and Batteries required by the Solar System. The application contains the default Wattage of every appliance but the user can also enter a custom value. In the advanced version the appliances are grouped together in to five categories namely entertainment, kitchen, air-conditioning, cleaning and lighting. Energy requirement of each category is calculated separately and displayed. The advanced version also calculates the rating of the Charge Controller and Inverter required by the Solar System. These are essential components of a Solar System. Additionally the full version also takes into account the System Efficiency, Offline vs Online Usage and Depth of Discharge. The advanced version also calculates the Peak Sun Hours using three different estimation methods. The estimation methods include use of NASA Solar Insolation Data, Half-Sine Model and Air Mass Formula. There is also a mechanism to calculate the tilt of the Solar Panels and the area required by the Solar Panels