Notepad Calculator is described as 'For jotting down quick calculations. Mix free form text with calculations and see the results appear in the right hand margin as you type' and is an website in the Education & Reference category. There are more than 10 alternatives to Notepad Calculator, not only websites but also apps for a variety of platforms, including Mac, Windows, Self-Hosted solutions and Linux. The best alternative is Numi, which is free. Other great sites and apps similar to Notepad Calculator are Soulver (Paid), OpalCalc (Freemium), NoteCalc (Free, Open Source) and Caligator (Free, Open Source).
Napkin is a unique mix between a notepad and a calculator. Doing quick calculations on your phone has never been easier! Features - Auto-save - Support for Variables - Auto-magically evaluates your math expressions - Napkin is fast - Dark/Light theme - No Ads
Wakari provides web-based Python data analysis via embedded iPython notebooks. Embedded IPython Notebook Work in the cloud with IPython notebook. You may also publish your notebooks or fork a notebook directly to your workspace.