💵 LLM API Cost Calculator

Enter your token volume once and see every model ranked from cheapest to priciest — GPT-4o, GPT-4.1, o1, Claude, Gemini, DeepSeek, and Mistral, side by side.

📊 Usage Details
Prompt + system message + context sent with each call.
Expected length of the model's response.
📈 Cost Ranking
Cheapest Model (Monthly)
Your Selection (Monthly)
Cheapest Cost/Request
Your Cost/Request
Priciest Model (Monthly)

🏆 Ranked: Cheapest to Priciest (monthly)

Monthly Cost by Model
Your Selection: Input vs Output
⚠️ Prices updated June 2026 — verify current rates on each provider's pricing page before budgeting. Ranking reflects standard real-time API pricing; OpenAI and Anthropic batch APIs can cut these numbers by roughly 50% for asynchronous workloads. All providers bill in USD.
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Enter your details and click Calculate to see results

Guide

About the LLM API Cost Calculator

With more than a dozen viable LLM APIs on the market in 2026 — from OpenAI's GPT-4o and o1 family to Anthropic's Claude Sonnet and Opus line, Google's Gemini models, and fast-moving open-weight options like DeepSeek V3/R1 and Mistral Large — picking a model by price alone has become genuinely hard to do in your head. This LLM API cost calculator takes one input/output token profile and one request volume and instantly ranks all 14 models from cheapest to priciest, so you can see exactly where your chosen model sits relative to every alternative at your specific usage pattern.

How It Works

You enter the input tokens and output tokens for a typical request, plus how many requests you expect per day. The calculator applies each model's published per-million-token input and output price to compute a cost per request, then multiplies by your daily volume and by 30 to project a monthly cost for every model at once. Models are sorted from cheapest to most expensive monthly cost, and your chosen "primary" model is highlighted in the ranking, alongside the overall cheapest option, so you can see the price gap directly.

Why It Matters

The relationship between input price and output price is not the same across providers — a model that looks cheap on input tokens can be one of the pricier options once your output length grows, because output tokens are billed at 3-5x the input rate almost everywhere. Ranking every model side by side at your actual token mix avoids the common mistake of comparing headline "per 1M tokens" prices without accounting for how input-heavy or output-heavy your workload really is.

Tips for Accurate Results

  • Measure your real input and output token averages from production logs rather than guessing — a 20% miss on output tokens can meaningfully shift the ranking.
  • Re-run the comparison whenever you change your prompt template or add retrieval context, since both change your input token count.
  • Remember that batch APIs (OpenAI, Anthropic) can cut the shown costs roughly in half for workloads that can tolerate a 24-hour turnaround.
  • Factor in quality, not just price — a cheaper model that requires more retries or a longer prompt to get comparable output quality may not actually save money.
  • Revisit this comparison periodically; per-token pricing across all providers has changed multiple times per year historically.
About

Reading the Cost Comparison

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Cheapest ≠ Best Fit

The cheapest model at your token volume may still lack the reasoning depth, context window, or reliability your task needs. Use the ranking to shortlist a few affordable candidates, then validate quality before committing production traffic.

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Output Tokens Dominate Cost

Because output tokens are priced several times higher than input tokens on nearly every provider, trimming response length (structured output, lower max_tokens, stop sequences) often saves more than switching models entirely.

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Re-check Regularly

LLM pricing has shifted meaningfully multiple times a year across every major provider as new model generations ship. Bookmark this calculator and re-run it before renewing any budget or contract.

FAQ

Frequently Asked Questions

Common questions about comparing LLM API pricing

Which LLM API is cheapest in 2026?
Among mainstream providers, Gemini 1.5 Flash ($0.075/$0.30 per 1M input/output tokens) and GPT-4o mini ($0.15/$0.60 per 1M) are typically the cheapest general-purpose options, followed by DeepSeek V3. The exact ranking depends on your input-to-output token ratio, since output tokens are billed at a much higher rate across every provider.
Why does the ranking change based on my token counts?
Every model has a different ratio between its input price and output price. A model that looks cheap on input tokens can still end up expensive overall if your output tokens per request are large, because output tokens are billed at 3-5x the input rate on most providers. This calculator recomputes the ranking every time you change your input, output, or volume numbers.
Does this include OpenAI's or Anthropic's batch API discount?
No — this calculator shows standard, real-time API pricing. Batch APIs from OpenAI and Anthropic can cut costs by roughly 50% for asynchronous, non-urgent workloads; if that fits your use case, apply a 0.5x multiplier to the numbers shown here for those providers.
How is monthly cost calculated?
Cost per request is (input tokens ÷ 1,000,000 × input price) + (output tokens ÷ 1,000,000 × output price). That figure is multiplied by your requests per day, then by 30 to estimate a monthly cost. Actual invoices may differ slightly due to provider-side rounding, minimum billing units, and any volume discounts you negotiate.
Should I always pick the cheapest model?
Not necessarily. Cheaper models often have smaller context windows or weaker reasoning on complex tasks, which can increase retries, hallucination-driven rework, or the need for a larger prompt to get the same quality — all of which add hidden cost. Use this calculator to see the price gap, then validate output quality before switching a production workload to a cheaper model.

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