LLM API Cost Comparison

How to Use the LLM API Cost Calculator

The LLM API cost comparison calculator comes down to three values that you enter yourself. You do not need to install anything or create an account—just know your approximate token usage and the rates for two models.

1. Tokens / month (M) — how many millions of tokens you use or plan to use in a month. The default is 10, meaning 10 million tokens per month.
2. Model A ($/1M) — the first model's rate per 1 million tokens. The default is $3.
3. Model B ($/1M) — the second model's rate per 1 million tokens. The default is $0.6.

As soon as you change a value, you see three results: Model A / mo., Model B / mo., and Annual difference. With the default values, you get $30, $6, and $288.

The rates entered in the calculator are examples only, and you can replace them with any numbers—your own estimates or amounts from a provider's pricing page. If you want to calculate in another currency, simply enter the rates in that currency: the calculator does not convert by exchange rate, so you decide the unit.

How to Calculate Monthly Model Cost and Annual Difference

The whole calculation is based on two multiplications and one subtraction. All you need is the number of millions of tokens and the rate per 1 million tokens for each model.

Monthly model cost = number of millions of tokens × rate per 1M tokens

Annual difference = (rate A − rate B) × number of millions of tokens × 12

The number 12 is simply the number of months in a year. Step by step, using the default values:

1. Model A: 10 million tokens × $3 = $30 per month.
2. Model B: 10 million tokens × $0.6 = $6 per month.
3. Monthly difference: $30 − $6 = $24.
4. Annual difference: $24 × 12 = $288.

Note that both monthly costs grow in proportion to usage, and the annual difference grows with them. Doubling the number of tokens will double the cost of Model A, the cost of Model B, and the annual difference, because the rates stay the same.

How to Compare Two Models with Different Rates per 1M Tokens

When comparing models, looking at the rate alone is not enough—what matters is the rate multiplied by your real token usage. That is why the same pair of models can look similar at low volume and very different at high volume.

• Positive annual difference means that, at the entered rates and usage, Model B is cheaper.
• A difference close to zero means both models cost practically the same, and factors other than price may decide the choice.
• A negative difference appears when Model B is the more expensive one. In that case, it is easiest to swap the rates so you can read the result as savings.

The default comparison shows the scale of the difference at 10 million tokens per month:

If you do not know how many tokens you will use, run the comparison twice—once for a cautious scenario with higher usage and once for a lower one. You will then see whether the model choice matters at your scale or is a secondary difference.

Limitations: No Input/Output Split, Cache, Batches, Free Tiers, or Taxes

The calculator is intentionally simple, so it is worth knowing what it does not cover. It assumes one rate for all traffic on a given model, while real pricing pages often have more than one rate.

• No split between input and output tokens — if a pricing page charges different rates, enter one averaged value in the calculator or calculate two separate scenarios.
• No cache — it does not include cheaper cache reads or the savings they can provide.
• No batches — it does not count batch processing discounts or other promotional billing terms.
• No free tiers — it does not subtract any free allowance you sometimes get at signup or as part of a subscription.
• No taxes, invoices, or additional fees — it does not add sales tax, VAT, or other charges that may appear on a bill.
• No current prices or exchange rates — you enter rates manually, so the calculator does not know what a provider charges today.

For these reasons, treat the result as an approximate reference point: it is great for an initial model comparison and budget planning, but it does not replace a provider invoice or an individual contract analysis. Before making a decision, check the current pricing and your actual terms.

How to Find Current API Pricing and Enter It in the Calculator

The rates in the calculator are examples, so for a serious comparison it is worth updating them with data from the model provider.

1. Go to the provider's pricing page and find the price table for 1 million tokens for the model you are interested in.
2. Check whether the price covers input tokens, output tokens, or both together. If the rates are different, calculate your average based on the proportion of requests and responses in your project.
3. Make sure all amounts are in the same currency. If they are not, convert them using the exchange rate you use for billing.
4. Enter the calculated rate for Model A and Model B in the appropriate fields, then set the number of millions of tokens per month.
5. Write down the date you checked the pricing—providers change terms, and the meaning of the comparison changes with them.

It is also worth calculating a pessimistic scenario with higher token usage and a conservative scenario with lower usage. This shows how much the annual difference depends on the scale at which you use the models.

Frequently Asked Questions

The rates in this calculator are estimates; before deciding, check the current API pricing for the models you compare.