From recipe
to next test.
A ceramic glaze calculator for understanding your chemistry, exploring adjustments, and keeping your firing notes together.
Free and open-source. This is the project website; install the self-hosted app to use the tools.
Four materials.
A closer look.
| Custer Feldspar | 45 |
|---|---|
| Silica | 25 |
| Whiting | 18 |
| EPK | 12 |
| K₂O | 0.2696 |
|---|---|
| Na₂O | 0.1539 |
| CaO | 0.5765 |
| Al₂O₃ | 0.6317 |
| SiO₂ | 5.6040 |
| Fe₂O₃ | 0.0045 |
Test note: alumina is above the typical cone 10 range used by the calculator. Fire a test tile to assess the result.
Computed from the README example. No fired result is represented. A calculation cannot establish glaze fit or food safety.
A place for the chemistry.
And the observations.
Keep the calculation and the firing record in the same workflow. Each new test is something you can return to.
Read the recipe
Convert a batch recipe to UMF. Examine oxide roles, silica-to-alumina ratio and estimated thermal expansion. Scale the batch when you're ready to mix.
Inside the chemistry engineChoose the next test
Explore material adjustments with the recipe optimizer. Compare calculated changes, then test the candidate on your clay body and firing schedule.
How optimization worksKeep the firing story
Bring recipes, firing notes and photographs together. Document the experiment from first idea to fired result, and share glaze libraries with your studio.
Explore the studio toolsAlso available: recipe organization, studio collaboration and the optional Kama assistant with local or cloud model support. Read the configuration guide.
The reference shelf
Jump straight to the problem you need solved: UMF calculation, CTE analysis, recipe scaling, Glazy integration, DigitalFire reference, or self-hosting setup.
Ceramic Glaze Calculator
Calculate glaze chemistry, understand recipe behavior, and plan the next test tile.
UMF Calculator
Convert recipes into Unity Molecular Formula, oxide roles, and SiO₂:Al₂O₃ ratios.
Glaze Recipe Calculator
Scale, document, compare, and improve ceramic glaze recipes.
CTE Calculator
Reason about crazing, shivering, and clay-body fit before firing.
Glazy Companion
Use OpenGlaze for private chemistry analysis alongside community recipe discovery.
DigitalFire Companion
Turn ceramic chemistry education into live recipe calculations.
Open Source Pottery Software
Keep studio knowledge in a transparent, modifiable MIT-licensed tool.
Self-Hosted Glaze Software
Run OpenGlaze locally or on your own server with private recipes.
Make room for it
in your studio.
Open-source software, on your own machine or server. Start with the documented Docker and SQLite setup.
- Explore the source
MIT licensed. Read it, adapt it, contribute. - Set up your workspace
Follow the installation and configuration guide. - Bring a recipe
Calculate, record, and plan your next test.
Frequently Asked Questions
What is OpenGlaze?
OpenGlaze is a free, open-source ceramic glaze calculator and studio workbench for potters and ceramic studios. It includes a UMF calculator, CTE analysis engine, computational recipe optimizer, a library of cone 6 and cone 10 recipes, and AI-powered glaze consulting — all self-hosted under the MIT license.
Is OpenGlaze really free?
Yes. OpenGlaze is completely free, open-source software under the MIT license. There are no paywalls, no subscriptions, and no feature gates. You can self-host it on your own server and keep full control of your glaze recipes. Read why we chose this model.
What is a UMF calculator for ceramics?
UMF stands for Unity Molecular Formula. A UMF calculator converts raw glaze recipes (percentages of materials like feldspar, silica, and kaolin) into a normalized molecular formula. This reveals the SiO₂:Al₂O₃ ratio, flux composition, and predicted surface qualities — essential for understanding and adjusting glazes. OpenGlaze calculates UMF automatically from any batch recipe.
How does the glaze recipe optimizer work?
The OpenGlaze recipe optimizer uses computational chemistry — not AI guessing — to suggest exact material adjustments. You set a target (e.g., specific CTE, matte surface, reduced running risk) and the engine grid-searches stoichiometric adjustments, ranks them by predicted outcome, and returns the top suggestions with before/after chemistry.
Is OpenGlaze a replacement for Glazy or DigitalFire?
No — OpenGlaze complements them. Glazy is a recipe database and community. DigitalFire provides deep ceramic chemistry education. OpenGlaze is a computational chemistry engine and glaze management tool. You can use community recipe references alongside OpenGlaze calculations.
Can I self-host OpenGlaze?
Absolutely. Self-hosting is the primary deployment model. Run it locally with SQLite, or deploy with Docker and SQLite for the supported self-hosted path. Works on a VPS, a Raspberry Pi, or any machine running Docker. The default installation stores recipes in SQLite; optional cloud integrations have their own data flows.