The calculator is used to test your eyesight and recognize the difference in color shades. After clicking on the first lighter field, the calculator will change colors and the countdown will begin. Each test takes 15 seconds. Search for a lighter field and click on it. Each subsequent test is more difficult. The test will be aborted if you do not give the correct answer within 15 seconds or if you make a wrong choice three times.

Use this calculator to calculate the "wind chill" temperature or apparent temperature, i.e. the temperature equivalent to humans, caused by the combined effects of air temperature and wind speed

With this statistical calculator You can easily calculate standard deviation, variance of standard deviation, population standard deviation, variance of population standard deviation and arithmetic mean. With this data analysis tool, you will see the calculations performed step by step along with the formulas used.