About Sumvia

Sumvia is a publisher of small, focused web utilities: calculators, converters, and other everyday tools that do one job clearly and correctly. The first tool is the Percentage Calculator; more utilities will be added as they are completed and tested.

What we are building

Most everyday calculations do not need an app, an account, or a spreadsheet — they need a fast page with clear inputs, an accurate answer, and an honest explanation of how that answer was produced. That is the whole product. Each Sumvia tool ships with the formula it uses, a set of worked examples, and enough plain-English explanation that you could reproduce the result by hand.

Browser-native, no accounts

Sumvia tools run entirely in your browser. The values you type into a calculator are processed on your device and are never sent to our servers. There is no registration, no login, and no stored user profile. This is a deliberate design constraint, not a temporary state: utilities should be usable instantly and leave nothing behind.

Clear calculations, tested logic

Every calculation engine on Sumvia is implemented as small, typed functions with automated tests covering standard inputs, decimals, negatives, zero values, and edge cases such as division by zero. The worked examples shown on tool pages are generated by the same code that powers the interactive calculator, so the documentation cannot drift from the implementation. You can read more about how this works on our methodology and accuracy page.

Verify consequential results

Sumvia tools are general-purpose aids for everyday arithmetic. They are not a substitute for professional advice, and results should be independently verified before being relied on for consequential financial, legal, tax, medical, or business decisions. Where a tool has known limitations, we say so on the page.

Get in touch

Found a problem, or want to suggest a tool? See the contact page — reports of suspected calculation issues are especially welcome and are treated seriously.