Instructions: for many people percentage calculation is not an easy task. These four calculators help to simplify it. In the first just enter the percentage and the number from which it must be inferred. In the second calculator is asked to enter two digits, the first of which is placed in relation with the second; by clicking on "Calculate result" you will know what percentage it represents. Third calculator determines the percentage increase (or decrease) between the first and the second digit. Fourth calculator lets you know the value of a number, after entering an absolute value and a percentage. Use the dot for decimals, not the comma.