# All online calculators

- Raoult's Second law and the freezing temperature.
Calculation of boiling point and crystallization (freezing) of non-electrolyte solutions.

- Rectangle area calculation by perimeter
Rectangle area calculation with known perimeter and aspect ratio

- Regular expression tester
This online calculator allows user to experiment with regular expressions.

- Regular polygon area from circumcircle
Calculates the area of the circumcircle and of the regular polygon from radius of circumcircle and number of sides

- Regular polygon, number of sides and length of side from incircle and circumcircle radii
This online calculator finds number of sides and length of side of regular polygon given the radii of incircle and circumcircle

- Regular polygon. Incircle and circumcircle
This online calculator determines parameters of circumcircle and incircle of a regular polygon

- Relative humidity to absolute humidity and vise versa calculators
First calculator converts relative humidity to absolute humidity for given temperature and barometric pressure. Second calculator converts absolute humidity to relative humidity for given temperature and barometric pressure

- Root and power
This calculator outputs desired root and power of entered number

- Russian non-working days
The calculator displays official day offs for the current year and the weekends adjacent to them. The calculator takes into account weekends shifts according to Russian Federation Government Decrees.

- Saturation vapour pressure
This online calculator computes saturation vapour pressure for given temperature and atmospheric (barometric) pressure

- Seasonal fluctuations. Seasonal indices. Constant mean method.
The study of periodic (seasonal) fluctuations. Calculation of average seasonal index by constant mean method.

- Second, third and other derivatives
Evaluates first, second third and other derivatives of a single argument function

- Shadow length
Gives a vertical object shadow length for given coordinates and time. Also calculates shadow growth during whole day.

- Shannon Entropy
This online calculator computes Shannon entropy for a given event probability table and for a given message

- Side length of a right triangle
Calculates the side length of a right triangle from two other sides using Pythagorean theorem. Created by user's request

- Side length of a triangle
This calculator computes side length of a triangle given two sides and angle between them (law of cosines)

- Side length of the regular polygon
Calculates the side length of the regular polygon circumscribed or inscribed to a circle. Created by user's request

- Side of regular polygon from polygon area
Calculates the side length of regular polygon given the area of the regular polygon and number of sides