A Histogram is a pictorial way of representing the data series in the form of rectangular bars of varying height. It gives the frequency distribution for the corresponding  equal class intervals. Here the frequency distribution represents width of the rectangular bars and range is given by area of class intervals. 
Histogram Calculator is a online graphing tool to calculate the given data series and create the histogram by your own. You just have to enter the given data series in the block provided and to get the histogram for the particular data.
So let us see how to draw the histogram for a given data:
Step 1 : For a given problem observe the data series. Arrange the data series in equal intervals and do the frequency distribution for it. This table is frequency table.

Step 2 : Using the frequency table plot a graph of range versus frequency distribution which gives you the histogram.