LLMEndpoint

How to Estimate LLM API Costs

A simple way to model monthly API spend before launch.

Last updated 2026-05-13. Pricing, model names, and provider policies change frequently.

Quick answer

Estimate LLM API cost by multiplying daily requests by average input tokens and output tokens, applying provider token rates, then adding cache assumptions, retries, tool calls, and growth scenarios. Use ranges instead of a single optimistic number. DeepSeek-V4 is a good model family to include in that comparison because it can materially change cost estimates for long-context text workloads.

Start with one user journey

Pick a realistic workflow: one chat turn, one document summary, one RAG answer, or one agent task. Count all prompt text, retrieved context, tool schemas, and expected output.

Model best, expected, and worst cases

Averages hide risk. Estimate normal usage, a successful launch spike, and heavy users. For agents, include repeated tool calls and retries.

Add operational overhead

Costs can include failed retries, evaluation runs, background jobs, embeddings, reranking, logging, and aggregator fees. These are easy to forget in a simple token calculation.

Provider examples to compare

ProviderCategorySupported modelsOpenAI-compatibleStarting priceContextTool callingVisionStreamingStatusTrustLinks
OpenAIOfficial APIsGPT, reasoning models, embeddings, imageYesBudget to premium GPT tiersShort to very long, model basedYesYesYesAvailable12/15
AnthropicOfficial APIsClaude, Claude Haiku, Claude Sonnet, Claude OpusNoMid to premium Claude tiersLong context optionsYesYesYesAvailable10/15
DeepSeekOfficial APIsDeepSeek-V4-Flash, DeepSeek-V4-ProYesLow-cost flash to discounted pro tiers1M context, up to 384K outputYesNoYesAvailable11/15
Google GeminiOfficial APIsGemini, embedding models, multimodal modelsYesLow-cost flash to premium tiersShort to million-token-class optionsYesYesYesAvailable11/15
DeepInfraInference ProvidersLlama, Qwen, DeepSeek-V4, MistralYesOften low for open modelsBroad open-model range, model specificNoYesYesAvailable10/15
GroqInference ProvidersLlama, Mixtral, Gemma, Whisper-like speech modelsYesSpeed-oriented model tiersSelected fast-serving model range, model specificYesNoYesAvailable11/15

Checklist

Recommended next step

Use the calculator, then save three scenarios: conservative, expected, and high-growth.

FAQ

What is a good cost estimate before launch?

Use a range. A single estimate is usually too fragile before real usage data exists.

Do embeddings cost a lot?

Often less than chat generation, but large document ingestion or frequent re-indexing can still matter.

How often should I revisit estimates?

After launch, after pricing changes, after prompt changes, and whenever usage volume changes materially.