Scientific Data

Constants

NIST Reference on Constants, Units, and Uncertainty

Covers the fundamental chemical and physical constants. Includes a conversion calculator factors for energy equivalents, along with background information for some constants.

Conversion Calculators

MegaConverter

Converts units of measurement in nearly 40 different areas, including ancient units of measurement, angles, astronomical measurements, density, energy, finance/interest, heat, kitchen measurements, speed, temperature, time, volume, weights, wind chill, and others.

Periodic Tables

Periodic Table of the Elements

From Los Alamos National Laboratory. Includes information on the history, sources, uses, and general prices of each element.

Weights and Measures