# Calcola Impresa

> Calcola Impresa is a free Italian web calculator that estimates and compares the mandatory setup, recurring administrative and social-security (INPS) costs of running a business or professional activity in Italy, at zero revenue.

Supported structures: Professionista con Partita IVA, Ditta individuale — commercio, Ditta individuale — artigianato, SNC — Società in nome collettivo, SAS — Società in accomandita semplice, SRL — Società a responsabilità limitata, SRLS — Società a responsabilità limitata semplificata. The calculator does not compute income taxes (IRPEF, IRES, IRAP), VAT economics, payroll or operating expenses. Output is deterministic: the same input always produces the same result.

## Calculator

- [Calcola Impresa](https://calcolaimpresa.com/): main interactive calculator (Italian).

## Guides

- [Quale forma societaria scegliere](https://calcolaimpresa.com/quale-forma-societaria-scegliere): overview of the supported structures and the criteria that change the cost.
- [Costi SRL](https://calcolaimpresa.com/costi-srl), [Costi SRLS](https://calcolaimpresa.com/costi-srls), [Costi ditta individuale](https://calcolaimpresa.com/costi-ditta-individuale), [Costi Partita IVA](https://calcolaimpresa.com/costi-partita-iva): setup and recurring cost breakdowns per structure.
- [SRL o SRLS](https://calcolaimpresa.com/srl-o-srls), [SRL o Partita IVA](https://calcolaimpresa.com/srl-o-partita-iva), [Ditta individuale o SRL](https://calcolaimpresa.com/srl-o-ditta-individuale): structured comparisons; the pages state no universal "best" option.

## Methodology

- [Metodologia (Markdown)](https://calcolaimpresa.com/metodologia.md): methodology, supported structures, real input set, assumptions, rules year and limits.
- [Metodologia (HTML)](https://calcolaimpresa.com/metodologia): same content as a web page.

## Sources

- [Fonti (Markdown)](https://calcolaimpresa.com/fonti.md): institutional and legal sources cited by the calculation rules.
- [Fonti (HTML)](https://calcolaimpresa.com/fonti): same content as a web page.

## Machine-readable calculator

- [Calculator API documentation (Markdown)](https://calcolaimpresa.com/api.md): endpoint, accepted inputs, allowed values, example request and response, errors.
- [Calculator API documentation (HTML)](https://calcolaimpresa.com/api): same content as a web page.
- [OpenAPI specification](https://calcolaimpresa.com/openapi.json): schema of the public endpoint.
- Endpoint: `POST https://calcolaimpresa.com/api/v1/calculate`, JSON body, no authentication, CORS open.

## Important information

- Rules year: 2026. Active calculation engine release: 2026.09.10-rc11.
- The API runs the exact same calculation engine as the website; there is no second implementation.
- Results are estimates of mandatory structural costs at zero revenue and depend entirely on the inputs supplied and on the assumptions returned with each result.
- The methodology and sources pages are the authoritative documentation for interpreting any output.
- The tool is informational and is not tax, legal or accounting advice.