UK-based independent AI efficiency projectEvidence before claims · 2026

A Practical API-Cost Scenario: Inputs, FX Date and Limits

Input, cached-input and output quantities feed dated provider rates and a dated currency conversion, with exclusions stated.

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Token Optimisation

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Classification: CALCULATED illustrative scenario using editable inputs—not observed workload spend or a plan recommendation.

API Cost Scenario: Keep Inputs, Rates, FX Date and Limits VisibleCALCULATED SCENARIO METHOD · NOT ACTUAL SPEND. INPUT / CACHE / OUTPUT → DATED RATE SOURCE → FX DATE / CURRENCY → CALCULATED ESTIMATE. A calculator scenario is calculated from entered assumptions; it is not a record of actual provider spend.CALCULATED SCENARIO METHOD · NOT ACTUAL SPEND1INPUT / CACHE / OUTPUT2DATED RATE SOURCE3FX DATE / CURRENCY4CALCULATED ESTIMATELabel every quantity and unit · Keep rate and FX dates visible
CALCULATED SCENARIO METHOD · NOT ACTUAL SPEND. A calculator scenario is calculated from entered assumptions; it is not a record of actual provider spend.

A monthly API estimate is reproducible only when request volume, current and target token counts, cache share, output usage, model, rates and currency conversion are visible. The number is not a bill unless those inputs match real traffic and every charge category is included.

One calculator scenario

The Context Cost Calculator’s illustrative GPT-6 Luna scenario uses 10,000 requests per month, 12,000 current input tokens per request, 8,000 target input tokens, 50% and 40% cached-input shares, and zero output tokens entered for both sides. It uses displayed USD rates of $0.10 uncached input, $0.01 cached input and $0.50 output per million tokens. Zero output is an example input, not an observed workload count.

With those assumptions and the ECB reference conversion dated 1 October 2026, the calculator displays about £4.9873 current and £3.8689 target, a calculated difference of £1.1184. This result depends on the example’s request count, cache shares, price preset and FX reference. It is not observed spend or a guaranteed saving.

Check the boundaries

The scenario excludes possible cache-write or storage treatment, tool/grounding fees, taxes, discounts and quality/retry effects. Provider price pages can change; recheck the official source and verification date. Compare accepted work rather than token volume alone.

Use the calculator to change inputs and view price and ECB sources. Subscription mode is different: the £89 Pro 100 charge is user-recorded and the benchmark is in progress, so no per-token subscription cost is implied.