The Online Gradient Calculator is a free online tool that you can use to calculate the ratio of two colors. A gradient is a gradual change in one property (such as color) of a defined area. Online gradient calculators are the most common types of gradient calculators which are used to compute the colors which are required to give a smooth transition between two or more colors. The color of the object can be changed by using the color picker tool. Gradient Calculator: 1 st horizontal coordinate 1 st vertical coordinate 2 nd horizontal coordinate 2