# All online calculators

- Moonphases
Moon's age and phase calculation

- Mortgage calculator
- Nautical measurement units
Nautical mile, sea mile, cable

- Nominal interest rates сomparison
Сalculation of the effective interest rates for a given nominals

- Normal distribution
Plots the CDF and PDF graphs for normal distribution with given mean and variance.

- Number of agents in call center
The calculator works out number of call center agents using Erlang C formula for given call load and service level.

- 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.

- 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

- 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

- Parallel and perpendicular lines on a plane
This online calculator checks lines' slopes to see if they are parallel or perpendicular

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

- Pearson correlation coefficient
The calculation of the correlation coefficient of two random variables