NIST Digital Library of Mathematical Functions (DLMF)
The NIST Digital Library of Mathematical Functions (DLMF) serves as the authoritative, peer-reviewed successor to the Abramowitz and Stegun Handbook
Calculation
Plastic Molding & Injection Price Calculator
Great for rapid estimations of the cost of your next plastic injected part. It has a nice database of plastic
GeoGebra Scientific Calculator
Basic but does it well, with history, fractions and all features you want from a scientific calculator: GeoGebra Scientific is
Free FEM to be installed or online
FEM software. Install is normally required (Mac, Windows, Linux) … but an online version is available (look at the right
Framacalc online collaborative spreadsheet
Not the most feature-rich spreadsheet, but ZERO install or registration: Framacalc is a collaborative, web-based spreadsheet service hosted by Framasoft
MH-Audio Sound and Audio Calculators (Archive)
A very good resource for online Audio Calculators, classified into 6 categories: Loudspeaker Crossover Acoustic Electronic Turntable Various that really
The On-Line Encyclopedia of Integer Sequences (OEIS)
The largest online integer sequences database, searchable. It provides a searchable interface to identify sequences by numerical terms, keywords, or
Online Units Converter
Efficient and well organised (be sure to look at the “by Family” drop-down and not stay at the “Most Popular”
Wolfram Alpha Science Reference & Computational
Provides engineering information and problem solving techniques and maths, all powered by a powerful search engine: WolframAlpha functions as a
Statistics Tables
Provides all the statistical tables when MS Excel has no formula to compute it automatically. All these tables here are