LLM Cost Calculator

OpenAI API Pricing 2026

The most widely-used LLM API. GPT-5.5 and GPT-5.4 are the current frontier tiers; o3-pro and o4-mini lead the reasoning tier. OSS 120B offers open-source quality at near-free pricing.

Pricing verified 2026-08-03. Sourced from platform.openai.com/docs/pricing.

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OpenAI Model Pricing

Prices in USD per 1M tokens

ModelInput / 1MOutput / 1MContext
GPT-5.6 Luna
OpenAI cost-sensitive GPT-5.6 tier; 1.05M context
$0.2$1.21,050,000
GPT-5.6 Sol
OpenAI flagship for complex professional work; 1.05M context
$5$301,050,000
GPT-5.6 Terra
OpenAI balanced GPT-5.6 tier; 1.05M context
$2$121,050,000
GPT-5.5
Latest OpenAI frontier model; 272K context standard tier
$5$30272,000
GPT-5.5 Pro
GPT-5.5 Pro; 1M context; max capability tier
$30$1801,050,000
GPT-5.4
Strong coding & professional workloads; 272K context standard tier
$2.5$15272,000
GPT-5.4 Mini
Best mini model for coding, computer use, and subagents
$0.75$4.5272,000
GPT-5.4 Nano
Ultra-low-cost GPT-5.4 tier for classification and routing
$0.2$1.25272,000
GPT-5.4 Pro
GPT-5.4 Pro; 1M context; enterprise workloads
$30$1801,050,000
GPT-5 Pro
GPT-5 Pro; 400K context; heavy inference
$15$120400,000
o3 Deep Research
o3 with deep-research mode; extended reasoning budget
$10$40200,000
o4 Mini Deep Research
o4-mini deep-research; cost-effective research tasks
$2$8200,000
GPT-5 Codex
GPT-5 Codex; 400K context; coding-optimized
$1.25$10400,000
GPT-5 Mini
Previous-gen budget model; GPT-5.4 Mini is the current mini tier
$0.25$2128,000
GPT-5
Previous flagship; use GPT-5.5 for new projects
$1.25$10128,000
GPT-5 Nano
GPT-5 Nano; 400K context; ultra-cheap classification & routing
$0.05$0.4400,000
gpt-oss-120b
OpenAI open-source 120B; runs on Groq/Together at low cost
$0.04$0.17131,072
o3 Pro
o3 Pro; extended thinking compute; top-tier reasoning
$20$80200,000
GPT-4.1
Previous production tier with 1M context; superseded by GPT-5.4
$2$81,000,000
GPT-4.1 Mini
Previous mid-tier; 1M context window
$0.4$1.61,000,000
GPT-4.1 Nano
Previous budget tier; GPT-5.4 Nano is cheaper for new workloads
$0.1$0.41,000,000
o3
Flagship reasoning; use when o4-mini accuracy is insufficient
$2$8200,000
o4-mini
Best-value reasoning model; chain-of-thought built in
$1.1$4.4200,000
o1-pro
OpenAI reasoning model; verify current availability in the official rate card
$150$600200,000
o3 Mini
OpenAI reasoning mini model; verify current availability in the official rate card
$1.1$4.4200,000
o1
OpenAI reasoning model; verify current availability in the official rate card
$15$60200,000
GPT-4o-mini
OpenAI budget model; verify current availability in the official rate card
$0.15$0.6128,000

How to read these estimates

The monthly table assumes 70% input tokens and 30% output tokens. It is a consistent comparison baseline, not a prediction of your workload. Actual bills can also include cached-input discounts, batch pricing, tool calls, minimum charges, regional differences, retries, and taxes.

The linked source is the provider's pricing documentation. Verify the current rate card and model availability before committing to a budget.

Estimated Monthly Cost (70% input / 30% output split)

Model1M tokens/mo10M tokens/mo100M tokens/mo1B tokens/mo
GPT-5.6 Luna$0.500$5.00$50.00$500
GPT-5.6 Sol$12.50$125$1,250$12,500
GPT-5.6 Terra$5.00$50.00$500$5,000
GPT-5.5$12.50$125$1,250$12,500
GPT-5.5 Pro$75.00$750$7,500$75,000
GPT-5.4$6.25$62.50$625$6,250
GPT-5.4 Mini$1.87$18.75$188$1,875
GPT-5.4 Nano$0.515$5.15$51.50$515
GPT-5.4 Pro$75.00$750$7,500$75,000
GPT-5 Pro$46.50$465$4,650$46,500
o3 Deep Research$19.00$190$1,900$19,000
o4 Mini Deep Research$3.80$38.00$380$3,800
GPT-5 Codex$3.88$38.75$388$3,875
GPT-5 Mini$0.775$7.75$77.50$775
GPT-5$3.88$38.75$388$3,875
GPT-5 Nano$0.155$1.55$15.50$155
gpt-oss-120b$0.079$0.790$7.90$79.00
o3 Pro$38.00$380$3,800$38,000
GPT-4.1$3.80$38.00$380$3,800
GPT-4.1 Mini$0.760$7.60$76.00$760
GPT-4.1 Nano$0.190$1.90$19.00$190
o3$3.80$38.00$380$3,800
o4-mini$2.09$20.90$209$2,090
o1-pro$285$2,850$28,500$285,000
o3 Mini$2.09$20.90$209$2,090
o1$28.50$285$2,850$28,500
GPT-4o-mini$0.285$2.85$28.50$285

Frequently Asked Questions

How much does OpenAI LLM API cost?

OpenAI offers 27 models ranging from $0.040/1M to $150.00/1M input tokens. The most widely-used LLM API. GPT-5.5 and GPT-5.4 are the current frontier tiers; o3-pro and o4-mini lead the reasoning tier. OSS 120B offers open-source quality at near-free pricing.

Is OpenAI cheaper than self-hosting?

For low-volume workloads (under 100M tokens/month), cloud APIs like OpenAI are almost always cheaper than purchasing and maintaining GPU hardware. Use our calculator to find the exact break-even point for your usage.