OSVčalc

OSVcalc helps Czech self-employed people (OSVČ, main or secondary activity) work out how much money to set aside for taxes. Tell it what has been paid to you so far this year and it returns what to have saved right now, on top of any advances already paid.

Tools:

• calculate_osvc_taxes: computes income tax (15% / 23%, minus the taxpayer credit and any credits and deductions you enter), the social and health insurance settlement, VAT registration status, a comparison of výdajový paušál, actual expenses and paušální daň, a year-end projection with the monthly amount to save, and a filing guide with where and how much to pay. Supports employment income alongside the business (souběh). Replies in English or Czech.
• get_field_guide: lists every input the calculator accepts, with the same explanations as the web app, so an assistant can walk a user through their situation before running a calculation.

Both tools are read-only, stateless and need no account, API key or setup. Nothing is stored. The same calculator is available at osvcalc.cz.

Results are estimates, not tax advice.