# All online calculators

- Time Span Calculator
This online calculator computes how much time is passed between two time points, specified in hours and minutes.

- Time units
Calculator expresses time interval in different time units.

- Time zones
The calculator shows the current time, universal time, and time for the selected city

- Time. Total sum
Calculator sums up input time intervals

- Tips and tricks #10: Dynamic table columns
This article describes how to work with dynamic columns in your calculator

- Tips and tricks #1: How to set output value
This article describes process of calculator creation and how to set output value.

- Tips and tricks #2: How to make calculator translatable into different languages
This article describes the process of adding translation support to the calculator, so it can be translated into different languages.

- Tips and tricks #3: How to make calculator with custom errors
This article describes the process of adding custom errors to the calculator

- Tips and tricks #4: How to make calculator with table output
This article describes how to make calculator which outputs results in table format

- Tips and tricks #5: How to show/hide input and output controls in a calculator
This article describes how to control visibility of input and output controls in a calculator

- Tips and tricks #6: How to make calculator with virtual keyboard
This article describes how to create calculator with virtual keyboard using SVG image

- Tips and tricks #7: How to make calculator with SVG image map
This article describes how to create calculator with image map using SVG image

- Tips and tricks #8: How to reuse existing calculator
This article describes process of reusing another calculator's logic (algorithm) in your calculator.

- Tips and tricks #9: Big numbers
How to use big number input and PCR library.

- Ton-kilometer. Conversion based on the cost of a kilometer
Calculation of a cost of ton-kilometer

- Torus
Volume and surface area of torus.

- Total square
This calculator calculates total square as sum of squares of entered rectangles

- Total time
- Total time
This calculator allows you to carry out the addition of the time - it displays the total, the average, minimum and maximum.

- Total volume
This calculator calculates total volume as sum of volumes of entered rectangular parallelepipeds.