Calculators and Conversion Tools
Here is a list of online calculators that you may find useful. All of these calculators are free.
Online scientific and statistical calculator.
The coolest calculator on the web.
Desmos is a free online graphic calculator.
Calculator for every formula, with unit conversion and printable calculation history built in.
Designed to provide a basic, easy-to-use set of graphing functionality for algebra, pre-calculus, calculus and more...
This is the biggest calculator I have seen!
Online calculator with the potential to share calculations.
Convert It! - Convert just about anything to anything else. Over 5,000 units, and 50,000 conversions.
Convert acres to hectares, Btu/hour to horsepower, centimeters to inches, degrees to radians, feet to miles, furlongs to feet, liters to gallons, and more.
Metric Conversion Card - Use this easy chart to convert inches to centimeters, pounds to kilograms, Fahrenheit to Celsius, and more.
Calculator Tools and Apps
This is a comprehensive lost of tools and Apps for calculating.
Time Zone Converters
World Time Server
World Time Server shows current time and date in cities and countries in all time zones, automatically adjusted for local Daylight Saving Time rules. Convert times from one location to another or even check current international weather conditions.
Sometimes Google is enough if we want to know the exact time in a specific city. All we need to enter is “time (city name)”, as you see on the example, and we will see what the exact time is in that city. For example, if we want to find out the current time in New York, we need to type “time New York” into Google.
World Time Buddy
World Time Buddy (WTB) is a cross between a time zone converter, a world clock converter, and an online meeting scheduler. It's one of the best online productivity tools for those often finding themselves traveling, in flights, in online meetings or just calling friends and family abroad.
Time Zone Converter
This is another tool that can help you calculate difference in time zones. All you need to do is select the two cities you want to compare and then click on the “Convert” button. The difference will be presented to us by using UTC time.
Time Zone Check
Time Zone Map helps us get a visual representation of the different time zones all over the world. You can also search for a specific city at the bottom of the screen. It is yet another tool that can be very useless for frequent travelers, especially those who travel on business and need to make it to meeting and conventions on time.