Online Calculators & Conversion Tables
Look here for information about measurement systems, units, and related topics, as well as online calculators and software for unit conversions. You'll also find calculators for pH, temperature, molecular weight, and other chemistry figures.
Temperature Converter
Here's a handy online converter for temperatures. Simply enter your known temperature (Kelvin, Celsius, Fahrenheit) and the other values will appear. It's much easier than trying to remember the formulas or do the math!
Here's a handy online converter for temperatures. Simply enter your known temperature (Kelvin, Celsius, Fahrenheit) and the other values will appear. It's much easier than trying to remember the formulas or do the math!
Basic Online Calculator
Sometimes you just need to use a quickie calculator! Here's one for addition, subtraction, multiplication, and division.
Sometimes you just need to use a quickie calculator! Here's one for addition, subtraction, multiplication, and division.
Unit Conversion Worksheets
Use these printable worksheets to practice unit conversions. These pdf questions and answers will test your understanding of metric-metric, metric-English, and temperature conversions.
Use these printable worksheets to practice unit conversions. These pdf questions and answers will test your understanding of metric-metric, metric-English, and temperature conversions.
Balancing Chemical Equations
Here is a step-by-step tutorial for balancing chemical equations, along with a worked example. This is a must-read for students of general and introductory chemistry!
Here is a step-by-step tutorial for balancing chemical equations, along with a worked example. This is a must-read for students of general and introductory chemistry!
Calculating Concentration
Do the units for solution concentration confuse you? Get definitions and examples for calculating percent composition by mass, mole fraction, molarity, molality, and normality. I've also included a bit of information on dilutions.
Do the units for solution concentration confuse you? Get definitions and examples for calculating percent composition by mass, mole fraction, molarity, molality, and normality. I've also included a bit of information on dilutions.
Chemistry Problems - Worked Examples
This is an ever-growing collection of worked chemistry problems. The examples are grouped according to subject matter.
This is an ever-growing collection of worked chemistry problems. The examples are grouped according to subject matter.
Constants, Prefixes, Conversion Factors
This is a set of tables with some useful physical constants, conversion factors, and unit prefixes. They are used in many calculations in chemistry, as well as in physics and other sciences.
This is a set of tables with some useful physical constants, conversion factors, and unit prefixes. They are used in many calculations in chemistry, as well as in physics and other sciences.
Measurements & Conversions Quiz
Take a multiple choice quiz to test your comprehension of units, conversions, and significant figures.
Take a multiple choice quiz to test your comprehension of units, conversions, and significant figures.
Scientific Notation
Scientific notation uses exponents to express numerical figures. Here's an explanation of what scientific notation is, plus examples of how to write numbers and perform addition, subtraction, multiplication and division problems using scientific notation.
Scientific notation uses exponents to express numerical figures. Here's an explanation of what scientific notation is, plus examples of how to write numbers and perform addition, subtraction, multiplication and division problems using scientific notation.
Significant Figures in Measurements and Calculations
This article discusses the use of significant figures in taking measurements and performing calculations. Learn about significant figures, uncertainty, accuracy, precision, rounding, and truncating. Losing significant figures and effects of exact numbers are also described.
This article discusses the use of significant figures in taking measurements and performing calculations. Learn about significant figures, uncertainty, accuracy, precision, rounding, and truncating. Losing significant figures and effects of exact numbers are also described.
Top Calculators
Choices, choices! Read this to help select a scientific, graphing, printing, programmable, desktop, solar, or wallet calculator. Then compare prices for your favorites.
Choices, choices! Read this to help select a scientific, graphing, printing, programmable, desktop, solar, or wallet calculator. Then compare prices for your favorites.
1976 Standard Atmosphere Calculator
These are online conversions for altitude, temperature, pressure, density, and speed of sound. Many different units are available.
These are online conversions for altitude, temperature, pressure, density, and speed of sound. Many different units are available.
A Dictionary of Units
A summary of most of the units of measurement to be found in use around the world today, together with the appropriate conversion factors.
A summary of most of the units of measurement to be found in use around the world today, together with the appropriate conversion factors.
ASCII Character Codes
The Indiana University Knowledge Base provides this table of decimal and hexadecimal equivalents for ASCII characters.
The Indiana University Knowledge Base provides this table of decimal and hexadecimal equivalents for ASCII characters.
ChemCalc - Calculate a Molecular Formula
Enter a chemical formula and ChemCalc will calculate it molecular formula, molecular mass, exact mass, and elemental analysis will plot an isotopic distribution graph. In addition to the calculator, the site offers FAQs, contact information, mailing lists, table of elements and their atomic mass, and section on known atom groups.
Enter a chemical formula and ChemCalc will calculate it molecular formula, molecular mass, exact mass, and elemental analysis will plot an isotopic distribution graph. In addition to the calculator, the site offers FAQs, contact information, mailing lists, table of elements and their atomic mass, and section on known atom groups.
Chemistry Calculators
There are online grams-to-moles, moles-to-grams, temperature, and ideal gas converters.
There are online grams-to-moles, moles-to-grams, temperature, and ideal gas converters.
Conversion and Calculation Center
ConvertIt.com's online calculators can perform unit, time zone, and currency conversions. There is also a reference section for geographical locations.
ConvertIt.com's online calculators can perform unit, time zone, and currency conversions. There is also a reference section for geographical locations.
Conversion Factors
This is a table of conversion factors to convert various units to their SI equivalents. It is not intended for people who prefer to use cgs or English units.
This is a table of conversion factors to convert various units to their SI equivalents. It is not intended for people who prefer to use cgs or English units.
Conversion Formulas
The US Geological Survey provides this table of common metric to English conversions.
The US Geological Survey provides this table of common metric to English conversions.
Conversion of Units
The Institute of Chemistry, Berlin, provides this easy to use online calculator for a host of different units. You simply choose input the starting value and unit and select the desired result.
The Institute of Chemistry, Berlin, provides this easy to use online calculator for a host of different units. You simply choose input the starting value and unit and select the desired result.
Conversion Table for Cooking
Botanical.com provides these English-to-metric and metric-to-English conversion tables for weights and measures.
Botanical.com provides these English-to-metric and metric-to-English conversion tables for weights and measures.
Converting Occupational Exposure Limits
Principles used in unit conversions of mg/m3 to ppm for gases and vapors. From the Canadian Center for Occupational Health & Safety.
Principles used in unit conversions of mg/m3 to ppm for gases and vapors. From the Canadian Center for Occupational Health & Safety.
ConvertIt.com
On-screen conversions transform one international unit to another – including time zones.
On-screen conversions transform one international unit to another – including time zones.
Decimal - Hexadecimal - Binary Conversion Table
From decimal 0 to decimal 255.
From decimal 0 to decimal 255.
Dictionary of Units
Système International history, units, definitions, and prefixes.
Système International history, units, definitions, and prefixes.
Distillation, Vapor Pressure, and Equilibria
Tables and calculations involving vapor-liquid equilibria. From Shuzo Ohe, Science University of Japan.
Tables and calculations involving vapor-liquid equilibria. From Shuzo Ohe, Science University of Japan.
eFunda: Units and Constants
A lot of information about units and unit conversion; includes also constants, information about SI, and unit prefixes.
A lot of information about units and unit conversion; includes also constants, information about SI, and unit prefixes.
Formula to Mass to Formula Applet
Enter formula and get mass; enter mass and get some empirical formulas. From Guillaume Cottenceau, Imperial College of Science, Medicine and Technology.
Enter formula and get mass; enter mass and get some empirical formulas. From Guillaume Cottenceau, Imperial College of Science, Medicine and Technology.
Fundamental Physical Constants
From NIST, latest values of the constants and background information.
From NIST, latest values of the constants and background information.
Grit and Microgrit Grading Conversion Chart
Convert from grit to mesh to microns to inches. From Reade Advanced Materials.
Convert from grit to mesh to microns to inches. From Reade Advanced Materials.
Guide for the Use of the International System of Units
Everything you need to know about SI. A NIST special publication, available as PDF file for download.
Everything you need to know about SI. A NIST special publication, available as PDF file for download.
How Many?
From Russ Rowlett, University of North Carolina, a comprehensive dictionary of units of measurement covering the English customary systems, the metric system, and the International System of Weights and Measures (SI).
From Russ Rowlett, University of North Carolina, a comprehensive dictionary of units of measurement covering the English customary systems, the metric system, and the International System of Weights and Measures (SI).
International System of Units
From NIST, essentials of the SI, background, and bibliography.
From NIST, essentials of the SI, background, and bibliography.
Internet French Property's Conversion Table
Converts metric, imperial, and US measurements.
Converts metric, imperial, and US measurements.
Mass Spec Tools
Online tools calculate exact masses, isotopic abundances, and perform other mass spectroscopy functions. Includes periodic table with mass spectra of elements. From Scientific Instrument Services.
Online tools calculate exact masses, isotopic abundances, and perform other mass spectroscopy functions. Includes periodic table with mass spectra of elements. From Scientific Instrument Services.
MegaConverter 2
This is an online converter for angles, area, astronomical distance, density, energy, financial interest, force, fractions-to-decimal, heat index, kitchen measures, length, mass, prefixes, power, pressure, resistance, speed, temperature, time, viscosity, volume, weight, wind chill... you name it!
This is an online converter for angles, area, astronomical distance, density, energy, financial interest, force, fractions-to-decimal, heat index, kitchen measures, length, mass, prefixes, power, pressure, resistance, speed, temperature, time, viscosity, volume, weight, wind chill... you name it!
Metric/Imperial Converter
Includes length, mass, and volume conversions.
Includes length, mass, and volume conversions.
Molecular Structure Calculations
This site will calculate molecular properties (bond lengths, angles, atomic charges, dipole moment, bond orders, molecular orbital energies) and the best Lewis structure that fits the molecular orbitals. The Lewis structure is given with formal electron pair localized bonds and the hybridization of the atomic orbitals used to form these bonds. The calculations take 1-2 hours to perform.
This site will calculate molecular properties (bond lengths, angles, atomic charges, dipole moment, bond orders, molecular orbital energies) and the best Lewis structure that fits the molecular orbitals. The Lewis structure is given with formal electron pair localized bonds and the hybridization of the atomic orbitals used to form these bonds. The calculations take 1-2 hours to perform.
Nephron Information Center
Easily convert mg/dL to mEq/L for a variety of ions and important biomolecules.
Easily convert mg/dL to mEq/L for a variety of ions and important biomolecules.
Notes on Acids and Bases
Short descriptions with examples and a Java applet that calculates [H+] and pH. From Gwen Sibert, Roanoke Valley Governor's School.
Short descriptions with examples and a Java applet that calculates [H+] and pH. From Gwen Sibert, Roanoke Valley Governor's School.
Online Metric Converter
Science Made Simple provides this program, which performs English to metric conversions for area, length, pressure, stress, speed, temperature, time, volume, weight, and fruit (I had to look that one up... it's apples and oranges).
Science Made Simple provides this program, which performs English to metric conversions for area, length, pressure, stress, speed, temperature, time, volume, weight, and fruit (I had to look that one up... it's apples and oranges).
OnlineConversion.com
This site does most conversions, with over 5,000 different units and 30,000 conversions. More unusual choices include clothing size conversions, light units, and number bases.
This site does most conversions, with over 5,000 different units and 30,000 conversions. More unusual choices include clothing size conversions, light units, and number bases.
pH Calculator
Converts from hydrogen ion concentration to pH and vice versa. From Henry Bungay, Rensselaer Polytechnic Institute.
Converts from hydrogen ion concentration to pH and vice versa. From Henry Bungay, Rensselaer Polytechnic Institute.
Physical Reference Data
SI units, atomic weights, ground states, atomic spectra, nuclear physics data. From National Institute of Standards and Technology.
SI units, atomic weights, ground states, atomic spectra, nuclear physics data. From National Institute of Standards and Technology.
Pressure Conversion Calculator
Interconvert Pa, torr, mm Hg, atm, lb/in2 and more. From the American Vacuum Society.
Interconvert Pa, torr, mm Hg, atm, lb/in2 and more. From the American Vacuum Society.
Roman Numeral and Date Conversion
There is an online converter between Arabic numbers and Roman numerals, dates in Gregorian or Julian calendars, and Roman to Gregorian dates. There is also a self-quiz.
There is an online converter between Arabic numbers and Roman numerals, dates in Gregorian or Julian calendars, and Roman to Gregorian dates. There is also a self-quiz.
Scientific Instrument Services
Software for many makes and models of mass spectrometers. Includes wealth of mass spectroscopy information and references including resins used for packing columns, exact mass calculators, supplies, and equipment.
Software for many makes and models of mass spectrometers. Includes wealth of mass spectroscopy information and references including resins used for packing columns, exact mass calculators, supplies, and equipment.
SI Units Conversion Table
Supports unit conversions from non-SI to SI. From TechExpo.
Supports unit conversions from non-SI to SI. From TechExpo.
Spektroscopy Online Spectroscopic Tools
There is a hydrogen-1 wizard, infrared wizard, mass spec wizard, and carbon-13 database. Databases and instructions for use are provided.
There is a hydrogen-1 wizard, infrared wizard, mass spec wizard, and carbon-13 database. Databases and instructions for use are provided.
Uconeer
A freeware units conversion program specifically for engineers, runs under Windows 9x/NT, from Katmar Software.
A freeware units conversion program specifically for engineers, runs under Windows 9x/NT, from Katmar Software.
Uncertainty of Measurement Results
From NIST, essentials of expressing measurement uncertainty.
From NIST, essentials of expressing measurement uncertainty.
Universal Currency Converter
It may not be universal, but it is certainly worldwide.
It may not be universal, but it is certainly worldwide.
US Metric Association
Promoters of US transition to metric system.
Promoters of US transition to metric system.
VassarStats: Statistical Computation Website
This is the site for you if you are calculating probabilities, distributions, frequencies, proportions, correlations, regressions, t-tests, ANOVA, ANCOVA, or are performing other statistical tests.
This is the site for you if you are calculating probabilities, distributions, frequencies, proportions, correlations, regressions, t-tests, ANOVA, ANCOVA, or are performing other statistical tests.
Web Pages that Perform Statistical Calculations
For computing probabilities, regression analysis, analysis of variance, and other statistical tests. From John C. Pezzullo.
For computing probabilities, regression analysis, analysis of variance, and other statistical tests. From John C. Pezzullo.
WinUnit
Free unit converter for Windows platforms from ESSCo. Commercial Windows API and COM versions for embedding unit conversions in user applications are also available.
Free unit converter for Windows platforms from ESSCo. Commercial Windows API and COM versions for embedding unit conversions in user applications are also available.
Wire Gauge Conversion Chart
Inches, gauge, and millimeters. From Reade Advanced Materials.
Inches, gauge, and millimeters. From Reade Advanced Materials.
World Wide Metric Co. Inc.
On-screen conversion calculators for length, weight, pressure, and volume.
On-screen conversion calculators for length, weight, pressure, and volume.
WWW Unit Converter
Applets deliver on-screen conversions. From Jan Derk Stegeman.
Applets deliver on-screen conversions. From Jan Derk Stegeman.