Blended token price
A single per-million-token figure that combines the input and output prices at an assumed ratio, so models can be ranked in one column. Obolith weights input 3x to output.
What it is
Formula used on Obolith: blended = (3 x input price + output price) / 4. The 3:1 ratio reflects a common workload shape - more prompt than reply - and matches the "blended price" other analyses use.
It is an assumption, not a fact about any specific app.
Why it matters
It gives a fast, honest way to sort ~200 models by cost. But if your workload is output-heavy (code, agents) the blended figure understates your cost; if it is input-heavy (long-context RAG) it overstates it. Sort by output or input directly when that matters.
Related concepts
Use it in Obolith
FAQ
Why 3:1 and not 1:1?
Most production chat and RAG apps send more context than they generate. 3:1 is a rough middle; the calculators let you use your real ratio.