What the calculator computes
Tokens to USD multiplies the input and output counts you provide by the corresponding per-million-token catalog rates. In single-count mode it shows two separate estimates. In input-plus-output mode it adds the two costs. The formula is visible beside the calculator.
Where rates can differ
Provider price sheets change. An aggregator route, model snapshot, service tier or long-context request can use another rate from a headline model entry. Always compare the exact model ID and route on your bill to the linked provider price sheet. The displayed catalog update date tells you when the data file changed, not when every provider last verified a particular SKU.
What a token count cannot reveal
A pair of text token counts cannot identify cached reads, cache writes, batch discounts, image or audio units, tool calls, web search, storage, taxes or credits. It may also omit billable reasoning unless the provider reports it inside output usage. Those categories must come from the provider dashboard or invoice.
Reconcile one billing period
Export model-level usage for a day or month. Apply the appropriate rate to each billing category, sum the line items, then compare with the invoice. Investigate large differences by checking retries, tier changes, cached tokens and alternative routes. If you see a stale or incorrect model rate on TokenRate, use the contact page with the model ID and official price link.