A dependency-free browser calculator that estimates monthly judge-model inference and observability-platform costs from explicit workload inputs. Version 1.1.0 covers five observability platforms and twelve public plans, with source-linked pricing registries verified on 2026-08-13. It keeps application traces, sampled telemetry, evaluated traces, judge calls, stored scores, observations, bytes, and retention separate. Unsupported overages return not_computable or a lower bound instead of an invented estimate. The release includes calculation tests, methodology, and a static GitHub Pages application. Results are planning estimates, not vendor quotes.