Molecular Weight
18.015 g/mol
H2O

Supports elements H through I. Enter formulas like H2SO4 or C6H12O6. Parentheses not supported.

Share:Copied!
Was this tool helpful?

Get a free API key + new tools as they ship

100 calls/day, no card, no spam. Built by one person, in public.

About Mol Weight

Mol Weight solves a specific problem that comes up daily for anyone dealing with this task: doing it once, fast, without an account. The goal was to keep the path from "open the page" to "get the result" as short as possible. No mandatory account, no cookie wall, no upsell at every step. If you find yourself doing this regularly, the rest of the utility suite covers most adjacent tasks with the same approach.

When you'd reach for Mol Weight

  • You're hitting the daily limit of a paid SaaS and need a backup option for a single quick job.

    Marketers and ops people whose primary tool is metered.

    Stay productive without burning credits.

  • You're on a public or shared machine and don't want to leave traces of what you're working on.

    Travelers, contractors, anyone working from a friend's computer.

    Nothing is uploaded, nothing persists if you're not signed in.

  • You need to handle a one-off task right before a meeting and don't have time to install anything.

    Anyone working remotely on a borrowed or restricted machine.

    Open the page, get the result, paste it into your doc — under a minute.

  • You're cleaning up a folder of files that accumulated over a project and need to standardize them.

    Designers, writers, and developers wrapping up deliverables.

    Drop each file in, copy the output, move on.

Frequently asked about Mol Weight

Do I need to create an account to use Mol Weight?
No. Mol Weight works without any signup. We only ask for an email if you decide to subscribe to a paid plan.
Are my files uploaded to a server when I use Mol Weight?
Mol Weight processes everything in your browser using local APIs. Your files never leave your device.
Can I use Mol Weight commercially?
Yes. The output of Mol Weight belongs entirely to you, with no licensing restrictions.
What browsers does Mol Weight support?
Every modern browser released in the last three years: Chrome, Firefox, Safari, Edge, Brave, Opera.
Does Mol Weight work on mobile?
Yes, Mol Weight is fully responsive and tested on iOS Safari and Android Chrome.

Explore More