Reliable and free online calculators can be found at Calculator.net, web2.0calc.com and Calculator-1.com, as of 2015. These sites provide various easy-to-use calculators for many different occasions.
Users can choose from basic, simple and scientific calculators on Calculator-1.com. The site provides instructions for use and answers to frequently asked questions.
Web2.0calc.com has a scientific calculator that performs advanced mathematical commands. The site also allows users to ask math questions or browse common math questions.
Calculator.net offers a wide variety of online calculators, including financial, math, weight loss, pregnancy, gas mileage and time zone calculators. The goal of the site is to become the go-to place for quick calculations.