A system and method for calculating an ambient light estimate using an image sensor in a camera of a device. An array of pixels is obtained using the image sensor. A matrix of grid elements is defined. Each grid element is comprised of multiple adjacent pixels of the array of pixels. A first measurement value is generated for a grid element of the matrix of grid elements based on the pixels associated with a respective grid element. A set of grid elements are identified having a first measurement value that satisfies a brightness criteria. A weighted measurement value is calculated using the identified set of grid elements. The ambient light estimate is calculated based on the weighted measurement value and the first measurement value.