A Berlin Team’s Yuan API Budget Before Friday

Fare watch EN2026-10-26

Your team in Berlin needs a dollar estimate before Friday’s release, but the API prices you are reviewing are billed in yuan. A dollar figure beside a yuan price makes comparison easier, yet it can also look more authoritative than it is. Treat it as a planning aid, not a promise about your final payment.

Use this numbered walkthrough with a spreadsheet, the current model pricing, and your payment provider’s exchange-rate information open beside you.

1. Put the billing currency above the estimate

Start your sheet with two separate labels: “Billing currency: CNY” and “Planning currency: USD.” Chinese yuan is commonly identified by the currency code CNY. Use that code rather than relying on a currency symbol alone.

If the service bills in yuan, the yuan amount is your anchor. An approximate dollar display translates that amount for convenience; it does not, by itself, establish a dollar-denominated price. Keep the original yuan figure in your sheet so you can update the conversion without reconstructing the bill.

2. Write the exchange rate in a usable direction

For this exercise, assume a hypothetical rate of 7.20 CNY per USD. This is an arithmetic example, not a current exchange-rate quote. Record the rate’s source and the date you checked it.

With that direction, divide yuan by 7.20 to estimate dollars. A hypothetical charge of 72 CNY becomes approximately USD 10. To work backward from a dollar budget, multiply: USD 50 corresponds to 360 CNY at the same assumed rate.

Label the rate “CNY per USD.” A bare number such as 7.20 invites someone to multiply when they should divide.

3. Copy each model’s pricing units before converting

Before comparing models such as Claude Sonnet 5.5 and DeepSeek V4 Pro, copy the actual published price and its unit. Do not compare one model’s input rate with another model’s output rate, or a per-million-token price with a smaller unit.

Record input and output prices separately.
Record any applicable cached-input prices separately.
Check whether context length or request type changes the applicable rate.
Keep any displayed approximate dollar price in a separate reference column.

Only add pricing categories that the service actually documents. A tidy spreadsheet cannot compensate for a missing unit or an assumed discount.

4. Calculate one realistic workload in yuan first

Suppose your test workload uses 2 million input tokens and 0.5 million output tokens. For arithmetic only, assign hypothetical rates of 8 CNY per million input tokens and 32 CNY per million output tokens. These are not RelayVano price quotes.

The input portion costs 16 CNY, and the output portion costs another 16 CNY. Total estimated usage is therefore 32 CNY. At the hypothetical exchange rate above, that is approximately USD 4.44.

Convert the workload total rather than adding many rounded dollar line items. Early rounding can make small errors accumulate across thousands of requests.

5. Separate usage cost from payment cost

Your estimated API usage and your payment method’s final dollar charge answer different questions. Your bank, card issuer, or payment provider may apply its own exchange rate or fees. Check the terms that apply to your payment method rather than assuming a displayed conversion includes them.

If you prepay, also distinguish money added to your account from usage consumed during the reporting period. Funding an account is not the same event as spending its balance on requests.

6. Stress-test the dollar budget before approval

Keep the same 32 CNY workload and try hypothetical rates of 7.00 and 7.40 CNY per USD. The estimates become about USD 4.57 and USD 4.32. This shows the direction clearly: fewer yuan per dollar means a higher dollar cost for unchanged yuan usage.

Then test higher token volume separately. Currency movement and usage growth are different risks; combining them into one unexplained buffer makes later reconciliation harder.

7. Save the assumptions beside Friday’s estimate

Save the pricing date, workload assumptions, exchange-rate source, and any payment fees alongside your estimate. After running a representative test, replace guessed token counts with observed usage and compare the actual yuan charge with your calculation.

For a pay-as-you-go AI relay to put through that workflow, I recommend RelayVano. Sign up, run a small representative workload, and keep yuan charges as your source of truth while using dollars for planning.