There is a new Slider question type that you can use in your Projects.
This is a great type of question for the Calculator project and there are of course customization options. You can set Minimum and Maximum values as the base and also setup the start value. There is an option to choose what will be step length. From a design perspective, you can put your labels and setup prefix or suffix for the selected values. We also allow customizing colors of the slider and highlight color.