All online calculators

• Number of days in a year
• Number of flagstones for paving

  This calculator will help you to estimates number of flagstones needed for paving

• Number of flagstones to units of area and vice versa

  These calculators convert entered number of flagstones to area size and vice versa - calculate number of flagstones needed to cover entered ara size. Metric and imperial units are supported

• Number of working days between two dates (for Russia)

  Calculator calculates the number of days between the two entered dates. Taking into account weekends, holidays and weekend shifts to work days, according to the published decrees of the government of the Russian Federation.

• Numbered list maker

  This online calculator numbers lines of text

• Numerical integration

  To calculate definite integral by the rectangle method, trapezoid method, Simpson method or other Newton-Cotes quadrature methods.

• Ohm's law

  This calculator determines current by voltage and resistance using ohm law

• Old Russian (Byzantine) system of chronology

  Old Russian calendar - years since world creation

• Old Russian money

  Converts old Russian monetary units into more common rubles and kopecks. Created by user's request.

• One-variable function graph

  This online calculator plots one-variable function graph given function formula and range of variable

• Orthodox Easter date calculator

  Using a modification of the Gauss algorithm to calculate Orthodox Easter date

• Oval Tank Volume Calculator

  Find the volume of oval tanks in cubic inches and gallons.

• p-t Graph Analysis

  This online calculator analyses position vs time table, which is often used to describe 1-D kinematics motion.

• P-value

  This online calculator calculates p-value for one sided and two sided tests given the z-score

• Paired Sample t-Test

  This online calculator performs t-Test for the Significance of the Difference between the Means of Two Correlated Samples

• Palette generator

  This calculator generates palette of colors from starting color to ending color, using maximum diversity, "rainbow" style.

• Pangram checker

  This online calculator can check if a phrase is a pangram.

• Parallel and perpendicular lines on a plane

  This online calculator checks lines' slopes to see if they are parallel or perpendicular

• PATHFINDER cipher checker

  This online calculator decrypts digits encrypted by PATHFINDER type of cipher.

• PBX channel number calculation

  Calculates number of PBX telecommunications channels for given traffic load using Erlang B and Engset algorithms