Read the graph to figure out the values for your starting and ending point. With a bar graph, find the category on one axis and the value will be the value at which the point or bar crosses the other axis. For example, if the bar goes up to the same height of $2,000 on the opposite axis, the value for that category equals $2,000.
Subtract the initial value from your ending value to find the numerical increase in the data. For example, if your savings account went up from $2,000 to $2,300, subtract $2,000 from $2,300 to get an increase of $300.
Divide the increase by the original amount and multiply the result by 100 to find the percent increase from the graph. In this example, divide $300 by $2,000 to get 0.15 and multiply 0.15 by 100 to get a 15 percent increase.