Molar Mass Calculator

Compute molar mass of a compound from its chemical formula (H2O, C6H12O6, etc.).

Calculator Science & Engineering Updated Apr 19, 2026
How to Use
  1. Enter a formula like H2O or Ca(OH)2.
  2. Parentheses and subscript multipliers supported.
Formula
Presets
Composition

Show Work

Enter values to see the step-by-step calculation.

Format

Basic
H2O · CO2 · NaCl
Parentheses
Ca(OH)2 · Al2(SO4)3
Subscripts
Digit after element = count

About the Molar Mass Calculator

The Molar Mass Calculator is a free tool for science and engineering work. It runs right in your web browser, so there is nothing to download. Compute molar mass of a compound from its chemical formula (H2O, C6H12O6, etc.).

How it works

Type your numbers into the boxes. The answer shows up right away — you do not have to press a button. If you change a number, the answer changes too. So you can try different numbers and watch what happens, or check an answer you worked out yourself. Just make sure each box has the right kind of number in it.

Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.

Frequently Asked Questions

Case matters?

Yes — element symbols are case-sensitive. "Co" = cobalt, "CO" = carbon + oxygen.

How do I use the Molar Mass Calculator?

Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.

Is it free? Does it work without internet?

Yes to both. It is free with no sign-up, and once the page has loaded it keeps working even with no internet.

Where does my data go?

Nowhere — every calculation runs on your own device. Nothing you enter is uploaded, logged, or stored.

Common Use Cases

Check your work

Worked it out yourself? Use the Molar Mass Calculator to make sure your answer is right.

Learn while you do it

Seeing what you put in and what comes out helps you understand how they fit together.

Get an answer fast

Type what you have and get the answer in seconds — on a phone, tablet, or computer.

Safe and private

Everything you type stays on your device. Nothing is sent to a server or saved.

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