Omni Calculator is described as 'Web/mobile calculator that solves concrete problems such as mortgage payment, gross margin, body mass index, break-even point, etc. It's very user-friendly, flexible and usable on web, mobile and as an embeddable web widget' and is a Calculator in the education & reference category. There are more than 100 alternatives to Omni Calculator for a variety of platforms, including Android, Windows, Web-based, iPhone and Mac apps. The best Omni Calculator alternative is Wolfram Alpha, which is free. Other great apps like Omni Calculator are SpeedCrunch, Fossify Calculator, Qalculate! and OpenCalc.