Support

Sumico for Windows and macOS. Last updated 27 September 2026.

A person reads every message. Write to mak.golub@gmail.com and say which version you are on and what you typed when it went wrong. A copy of the line is worth more than a description of it.

Where does it run?

On Windows and macOS, as a desktop app.

What can Sumico calculate?

Percentages in several plain English forms, units of length, mass, volume, data, speed, temperature and angle with SI prefixes, 160 fiat currencies and around 20 crypto tickers, dates, durations and time zones, variables, line references such as prev, sum and average, and the usual functions and number bases. The how-to has a live example of each.

What can Sumico not do?

It does not sync between devices, and it does not read numbers from other apps or web pages.

Does it work offline?

Yes. Calculation is entirely local. Exchange rates are cached, and a dated snapshot of rates ships inside the app, so currency lines still resolve with no connection. When a rate is older than Sumico considers current, it marks it as stale.

A rate looks wrong or out of date

Open Preferences and press Refresh rates now. If the marker stays, the source is unreachable and Sumico is falling back to the snapshot on purpose. You can switch the fiat source between ExchangeRate-API and the European Central Bank there as well.

Where are my calculations stored?

In the app's data folder on your own computer. Nothing is uploaded and nothing is shared between devices. See the privacy policy for what is stored and what leaves your computer.

My documents disappeared

Sumico keeps them only in its data folder, so removing that folder removes them with it. There is no copy on a server to restore from. To keep a copy elsewhere, use File, Export.

Does Sumico use AI?

No. There is no model, no API key and no prompt anywhere in the calculation path.

A line will not calculate

The message on the line is the actual reason: an unknown unit, an unknown name, a missing bracket. Unit names have to be spelled out in full, and a mixed expression like 5 feet 3 inches in cm works, while an abbreviated one does not.

I want to report a bug or ask for a feature

Same address: mak.golub@gmail.com. Bug reports that include the exact line and the expected answer get fixed first, because they turn straight into a test.