# Online Calculators & Conversion Tables

Metric Unit Prefixes

Metric units of measurement are all based on units of ten. Here is a list of the most common metric unit prefixes.

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!

Basic Online Calculator

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.

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!

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.

Chemistry Problems - Worked Examples

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.

Area, Perimeter & Volume Formulas

Perimeter, surface area and volume formulas are used for many chemistry calculations. You may need to find surface area and volume to determine density and concentration, for example. While it's a good idea to memorize these formulas, here a list of formulas to use as a handy reference.

Mean or Average - Calculate the Mean

It's very important to know how to calculate the mean or average of a set of numbers. Among other things, this will allow you to calculate your grade point average. However, you'll need to calculate the mean for several other situations, too.

Measurements & Conversions Quiz

Take a multiple choice quiz to test your comprehension of units, conversions, and significant figures.

Metric to Metric Conversions - Unit Cancelling Method

Here is a step by step example of a conversion between metric units. This illustrates how to cancel units to convert measurement units.

Metric Prefixes Quiz

How well do you know your metric prefixes? Quiz yourself with this ten question multiple choice self-test.

Perimeter and Surface Area Formulas

Perimeter and surface area formulas are part of the math used in common science calculations. You While it's a good idea to memorize these formulas, here is a list of perimeter, circumference and surface area formulas to use as a handy reference.

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.

Surface Area and Volume Formulas

Surface area and volume formulas are part of the math used in common science calculations. You may need to calculate surface area and volume to determine density, pressure and concentration, for example. While it's a good idea to memorize these formulas, here a list of surface area and volume formulas to use as a handy reference.

Table of Physical Constants

Need a value for a fundamental physical constant? This handy reference table contains commonly used physical constants used in chemistry.

Thermometer with Celsius and Fahrenheit Degrees

This thermometer is labelled with both Fahrenheit and Celsius degrees. Use it to compare the Fahrenheit and Celsius temperature scales or to look up conversions between them.

Why Is lb the Symbol for Pounds?

Have you ever wondered why lb is used as the symbol for the pounds unit? Here's the answer to the question.

1976 Standard Atmosphere Calculator

These are online conversions for altitude, temperature, pressure, density, and speed of sound. Many different units are available.

ASCII Character Codes

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.

Chemistry Calculators

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.

Conversion Formulas

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.

Conversion Table for Cooking

Botanical.com provides these English-to-metric and metric-to-English conversion tables for weights and measures.

ConvertIt.com

On-screen conversions transform one international unit to another – including time zones.

Decimal - Hexadecimal - Binary Conversion Table

From decimal 0 to decimal 255.

Distillation, Vapor Pressure, and Equilibria

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.

Fundamental Physical Constants

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.

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).

International System of Units

From NIST, essentials of the SI, background, and bibliography.

Internet French Property's Conversion Table

Converts metric, imperial, and US measurements.

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!

Metric/Imperial Converter

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.

Nephron Information Center

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.

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).

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.

pH Calculator

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.

Pressure Conversion Calculator

Interconvert Pa, torr, mm Hg, atm, lb/in2 and more. From the American Vacuum Society.

SI Units Conversion Table

Supports unit conversions from non-SI to SI. From TechExpo.

Uconeer

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.

Universal Currency Converter

It may not be universal, but it is certainly worldwide.

US Metric Association

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.

Web Pages that Perform Statistical Calculations

For computing probabilities, regression analysis, analysis of variance, and other statistical tests. From John C. Pezzullo.

World Wide Metric Co. Inc.

On-screen conversion calculators for length, weight, pressure, and volume.

WWW Unit Converter

Applets deliver on-screen conversions. From Jan Derk Stegeman.