Free Online Calculators for Engineers. Welcome to CALCULATOR EDGE, an online FREE Engineering. Calculators for Engineers and Students worldwide. Our website features more than few hundred calculators. Symantec Altiris Vs Microsoft Sccm Pricing. Electrical, Mechanical, Chemical, Electronics. Civil, Metallurgy, Oil Gas, Optical, Plastics. Ceramics, Physics, Maths and many more to come., if you have any. Calculators, engineering, mechanical, electrical, electronics, design, construction, manufacturing, consultant, layout, software, chemical, plastic, polymers. There is no particular symbol for no change. However, if you know the quantity that has not changed, for example represented by H, you could write H 0.