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AI API Cost Calculator | Estimate Token and Monthly Usage Costs

Project your AI API spend from token counts and provider rates — input, output, and cached tokens per request times your request volume. Compare models and providers side by side, and see daily, monthly, and yearly cost for any workload before you commit to it.

Last updated: August 2026 · Free · No sign-up required

Estimate AI API spending from input tokens, output tokens, cached tokens, model rates, and request volume.

How this tool works

How AI API costs are calculated

The calculator converts token counts and provider rates into an estimated per-request and total cost. Input, output, and cached-input prices are entered per million tokens. The estimate is not a billing statement because providers can apply tiers, batching, tools, storage, or other charges.

Pricing freshness

Use the provider’s current pricing page when entering rates. Record the model, source URL, effective date, and any cache or batch assumptions alongside a production estimate.

Worked example

Enter representative inputs, review the result, and adjust assumptions to compare scenarios.

Frequently asked questions

What is an AI API cost calculator?

It estimates usage cost from token counts, provider rates, and request volume. Enter the rates from the model provider you plan to use.

How are input and output tokens priced?

Providers usually publish separate prices per million input and output tokens. The calculator applies each rate to its corresponding token count.

Can cached tokens reduce cost?

They can when a provider offers a cached-input rate. Enter only the cached portion and use the provider’s current cached rate.

Does this include taxes or platform fees?

No. It estimates token usage only unless you include other charges in your own planning model.

Why can my invoice differ from the estimate?

Invoices can include tiered pricing, tools, batch discounts, storage, minimums, rounding, or tokenization differences.

Which providers can I compare?

You can compare any provider or model by entering its current input, output, and cached-input rates.

Quick reference

Model TierInput Price (per 1M tokens)Output Price (per 1M tokens)
Entry (e.g., compact model)$0.15$0.60
Standard (e.g., mid model)$0.50$1.50
High-capability (e.g., flagship)$2.50$10.00
Reasoning-heavy$5.00$15.00

Illustrative tiers for cost modeling — enter the exact prices from your provider's pricing page.

calculate Cost per request

Enter model prices and usage to see real API spend.

insights Budget alerts

Project monthly cost before your bill arrives.

lightbulb Pro tip

Batch prompts and cache system messages.

lightbulb Worked example

Estimating monthly cost for a chatbot doing 10,000 requests/day with 2,000 input + 500 output tokens each.

Result: Approx $4,050/month at $3/M input, $15/M output rates.

Formula & methodology

Formula: cost = ((uncached input tokens × input rate) + (cached input tokens × cached rate) + (output tokens × output rate)) ÷ 1,000,000 × requests

How AI API costs are calculated

The calculator converts token counts and provider rates into an estimated per-request and total cost. Input, output, and cached-input prices are entered per million tokens. The estimate is not a billing statement because providers can apply tiers, batching, tools, storage, or other charges.

Pricing freshness

Use the provider’s current pricing page when entering rates. Record the model, source URL, effective date, and any cache or batch assumptions alongside a production estimate.

Authoritative source: OpenAI API Pricing; also compare Anthropic and Google pricing pages

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