# All online calculators

- Percentage
This online calculator gives the percentage of the value. It also calculates the percentage of the sum (e.g. the income tax of the net salary) and the percentage of the difference (e.g. VAT of the gross amount).

- Petroleum product density
Petroleum product density conversion, according to GOST 3900-85

- Pipe cold bending. Flexure depth with main shaft.
Calculates the section flexure depth with pipe bender or bending machine to obtain given parameters.

- Polygon area
Online calculator which calculates area of a polygon given lengths of polygon sides and diagonals which split polygon to nonoverlapping triangles

- Power to the People
Power units converter.

- Pressure over a surface
This online calculator computes pressure, cause by given mass over given surface in gravity field. Result is displayed using different units of pressure

- Pressure units converter
Calculator which converts units of pressure

- Price based on running meter
This online calculator calculates the price of certain area based on price of running or linear meter

- Probability of given number success events in several Bernoulli trials
Gives probability of k success outcomes in n Bernoulli trials with given success event probability.

- Progressive tax
Calculates progressive tax according to tax rate table.

- Projection
Calculation of unknown parameters of projection using known parameters. Parameters are duration, maximum height, distance, initial velocity and angle.

- Proportion
This online calculator finds unknown member of proportion. Created by user's request

- Prospect distance from the ground and line of sight distance between two observers
Calculates the prospect distance from height at observer and line of sight distance between two observers.

- Racing laps table
This is generator of lap running order for kart racing. The goal is to let each racer to try each starting position/kart in random order.

- Random combination of numbers from specified range
This calculator randomly picks several numbers from specified range.

- 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.