Move the System.out.println call too if you want the last line to get a running total. That would eliminate the need for an if (income==-1) statement.
One thing, especially for money amounts, is that float is a poor data type. Amounts of around $2,000 have a representation error of about 1/10 cent and it doesn't take too many in a sum to get totals that don't quite balance. Use double (and scanner.nextDouble()) as your main floating point data type, unless you have a specific reason to sacrifice precision for storage.
//Tax rates, brackets, constants
final static double TAX1 = 0.10;
final static double TAX2 = 0.15;
final static double TAX3 = 0.33;
final static double BRACKET1 = 15000.00;
final static double BRACKET2 = 15001.00;
final static double BRACKET3 = 60000.00;
public static void main(String[] args) {
//Keyboard as input
Scanner keyboard = new Scanner (System.in);
//Defining variables
float income;
double tax=0;
double totalTax=0;
//Getting income from user
System.out.println("Please input the income, type -1 to end");
income=keyboard.nextFloat();
while(income!=-1){
if (income<=BRACKET1){
tax=income*TAX1;
System.out.println ("The tax on $" + income + " is $" + tax);
}
if (income==BRACKET2 && income<=BRACKET3){
tax=(BRACKET1*TAX1) + (income-BRACKET1)*TAX2;
System.out.println ("The tax on $" + income + " is $" + tax);
}
if (income>BRACKET3){
tax=(BRACKET1 * TAX1) + (BRACKET3-BRACKET1) * TAX2 + (income-BRACKET3)*TAX3;
System.out.println ("The tax on $" + income + " is $" + tax);
}
System.out.println("Please input the income, type -1 to end");
income=keyboard.nextFloat();
//Displaying total taxes when enter -1
if (income==-1){
totalTax=totalTax + tax;
System.out.printf("The total tax is $%.2f", totalTax);
}
//END OF PROGRAM
}
}
}
