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.

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.

Online calculator calculates the mode of series of distributing class intervals. You learn how to find the Modal value for a grouped data with different intervals between the data classes.

What would your weight be on other planets? How old would you be on another planet in the solar system? When would you have your birthday? You can check it with this calculator. You can also check what the weight of any item would be. The calculator will convert your weight and age into the weight and age you would have if you lived on Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune or Pluto.

How to calculate your Maximum Heart Rate (HRMAX)? Which heart rate zones to choose for training and how to calculate the heart rate zones? At what heart rate is the best fat burning, and at what will we increase our efficiency and improve the condition? The calculator for maximum heart rate and heart rate zones can help answer these questions. You will calculate both your maximum and optimal heart rate and select the heart rate ranges for the appropriate training.

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

With this statistical calculator, you will learn how to calculate the lower quartile, middle quartile, and upper quartile of an interval resolution series.

The CAPM calculator can be used to calculate the cost of equity, to evaluate the investment effectiveness of collective investment funds (open-end investment funds, pension funds, etc.), to study the efficiency of the stock market, etc.
The CAPM model allows to illustrate the relationship between the incurred systematic risk, otherwise known as market or non-diversifiable risk, and the expected rate of return.

The CAPM calculator in the form of CML allows you to calculate the expected rate of return from the so-called the effective portfolio (on the border of Markowitz's effective portfolios).

Using this calculator, you will calculate the pulse duration of the output pulse of the NE555 IC in monostable or astable mode of operation.

The Body Fat percentage calculator will help you calculate the amount of fat stored in your body. It uses a method of measuring skin folds in three different places on the body.

With this calculator, we will find out what ventilation efficiency should have depending on the size, height and type of room, e.g. in the kitchen, bathroom or toilet. The ventilation calculator will help us choose the right fan for the selected room, e.g. it will facilitate the selection of the hood for the kitchen.

With this calculator you can calculate voltage drops for single-phase and three-phase AC circuits calculated from the rated current. You will also calculate wire length, wire diameter, wire cross-sectional area, voltage or current.

With the converter, you can quickly translate any sentence into Morse code and vice versa. You can listen to the translated code, see it thanks to the light signals or, using the phone, feel it through vibration. Morse code is used nowadays mainly in amateur radio, it is also useful in many other areas of life.

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

The calculator will calculate how much water you should consume to supplement your daily requirement.

Rectangle calculator will help you calculate the diagonal of the rectangle, the side length, height, area of the rectangle.

With this calculator you will calculate the harmonic mean.

Trapezium (trapezoid) calculator will help you calculate the long diagonal of the trapezium, the short diagonal of the trapezium, the side length, height, area and perimeter of the trapezium.

Thanks to the calculator, you can easily calculate the amount of calories you burn every day. There are over 600 different activities available, from which you can choose those that were or will be performed on a given day and set the duration for each selected activity.

As a result, the calculator will provide the total duration of all activities, the sum of calories burned and the number of calories consumed for each activity separately, including the time of its execution. The calculator also tells you how many hours you need to constantly perform a given activity to lose weight by about 0.5 kg, taking into account your weight.

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