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.

Regular polygon calculator will help you calculate the diagonals of any regular polygon, side length, height, area, perimeter and radius of the circumscribed circle and the radius of the circle inscribed in a regular polygon.

Calculate how much you spend smoking, so how much you could save after quitting smoking.

The cone calculator will help you calculate the volume of the cone, the total area of the cone, the side area of the cone, the base area of the cone, the generatrix length and the radius of the cone base, and the volume of the sphere described on the cone.

With this calculator you will learn how to add in columns. You can check if the addition you have made is correct

With the help of the math calculator you can easily and quickly calculate the slope, the point of intersection with the Y axis.

The PV calculator helps us to calculate the current value of an investment, i.e. the PV (present value). The PV calculator calculates the amount we need today to obtain the given value in the future after a certain number of years and calculating the interest due, assuming that they will be capitalized (added to the capital) with the specified frequency (e.g. weekly, monthly, quarterly, semi-annually, annually) ie how much do you need today to get X in the future

With this statistical calculator, you will learn how to calculate a linear regression step by step.

Vernam cipher online encoder and decoder. Encrypt and decrypt any cipher created in a Vernam cipher.

Burrows-Wheeler transform online encoder and decoder. Encrypt and decrypt any cipher created in a Burrows-Wheeler transform.

The online calculator calculates the median called the median value or the average value, the most common numbers in the given set, i.e. the mode, by examining whether it exists, the arithmetic mean and sorts the data in ascending order.

You can calculate step by step any system of linear equations, both homogeneous and inhomogeneous with any number of unknowns by the Cramer's method. As a result, in addition to the solution, you also get a complete analysis and presentation of calculations step by step.

The calculator will help you choose the size of the bike, bike frame, wheel size depending on the type of bike, your height, leg length or age.

Pentagon calculator will help you calculate the long diagonal of the pentagon, the medium diagonal of the pentagon, the shorter diagonal of the pentagon, the side length, height, area of the pentagon, circumference and radius of the circumscribed circle and the radius of the circle inscribed in the regular pentagon.

Heptagon calculator will help you calculate the long diagonal of the heptagon, the short diagonal of the heptagon, the side length, heights, area of the heptagon, the radius of the circumscribed circle and the radius of the circle inscribed in a regular heptagon.

Using this calculator you can calculate the molar concentration of the solution, ie the number of moles of a given chemical substance that contains 1 liter of solution.

Trifid cipher online encoder and decoder. Encrypt and decrypt any cipher created in a Trifid cipher. You can use any shift and additionally a key for more precise text encoding.

The calculator is used to calculate the coverage of bills by profit before paying off the tax bill.

Using this calculator you can calculate the weight equivalent of acid.

With this calculator you will calculate the harmonic mean.