What does it cost to build an app with AI?
The honest answer is: it depends on the model strength you use, how many tokens your workflow burns, and whether you pay per token or by subscription. This calculator prices all of those, using the rates that applied on your build date — and it never dresses up an estimate as an exact figure.
How the estimate is built
TokenSpent multiplies each token type (input, output, cached input, cache write, reasoning) by the versioned rate for your chosen model on your chosen date. Actual money you were billed and the reconstructed API-equivalent value are shown as separate figures — never summed — so you can see both without double counting.
Subscriptions and opaque credits are inherently less precise, so those results are labeled lower confidence and shown as a range. Read the full pricing methodology.