Education & Student
Molar Mass Calculator
Molar Mass: it sums the atomic masses of every element in the formula to give the molar mass in grams per mole. Worked through below with real figures, and the calculator repeats the working on your own inputs — free, on-device, instant.
Enter your chemical formula and Molar Mass Calculator works out the molar mass in g/mol with summing the atomic masses in the formula — fast, free and private, with no sign-up or uploads.
About this calculator
It matters when grades, percentages or averages decide a next step and hand arithmetic is error-prone. The governing relationship: It sums the atomic masses of every element in the formula to give the molar mass in grams per mole. See it on real numbers: Water (H₂O): 2 × 1.008 + 16.00 = 18.02 g/mol . The calculator above applies the same steps to whatever you enter — computed locally, nothing sent anywhere.
How to use
- Type a chemical formula, such as Ca(OH)2.
- Use element symbols with optional counts and parentheses.
- Press Calculate to find the molar mass.
- Read the molar mass and the element composition.
Why use Molar Mass Calculator
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Uses standard formulas for quick educational estimates; check critical results before relying on them.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it for verifying a textbook result
Use it for science-fair preparation
Use it for tutoring and study groups
Use it when teaching a science concept
Use it when checking a homework answer
Use it when comparing two scenarios
Technical notes
Molar Mass Calculator sums the atomic masses of every element in the formula to give the molar mass in grams per mole.
Results assume ideal conditions and consistent units, so convert your inputs to the units shown before calculating.
Results are rounded for display; the underlying calculation keeps full precision.
FAQ
Does this support parentheses like Ca(OH)2?
Yes. The parser handles groups and multipliers, so Ca(OH)2 is read as one calcium, two oxygen, and two hydrogen.
What happens with an invalid formula?
The calculator reports the problem instead of guessing, and a blank formula is treated as a validation error.
Which elements are supported?
Common elements across the periodic table are included; an unsupported symbol is flagged rather than ignored.
Does the Molar Mass Calculator send my data to a server?
No. The Molar Mass Calculator runs entirely in your browser, so nothing you enter is uploaded, stored, or shared.
Worked example
Water (H₂O): 2 × 1.008 + 16.00 = 18.02 g/mol.