How do I use an AI token calculator to find my API cost?

Enter your average input tokens per call, average output tokens per call, the price per million tokens for input and output separately, and your monthly call volume. The AI token calculator multiplies each token count by its price per million, adds them for cost-per-call, then multiplies by monthly volume. Formula: Monthly Cost = ((Input Tokens / 1,000,000 x Input Price) + (Output Tokens / 1,000,000 x Output Price)) x Monthly Calls.

Why are output tokens more expensive than input tokens in LLM APIs?

Generating each output token requires a full forward pass through the model in an autoregressive loop. Reading your prompt requires only one forward pass total. That compute difference is why output tokens cost 3x to 5x more than input tokens across all providers.

How many words is 1,000 tokens?

For standard English prose, 1,000 tokens equals approximately 750 words. Code, URLs, and non-Latin scripts tokenise at 2x to 4x the rate of English text.

Which LLM API is cheapest in 2026?

As of May 2026, the cheapest standard-tier options are Google Gemini 2.5 Flash-Lite at $0.10 input / $0.40 output per million tokens, OpenAI GPT-4o mini at $0.15 / $0.60, and Anthropic Claude Haiku 4.5 at $1.00 / $5.00. Enter your usage into the AI token calculator above to see actual monthly cost at your call volume.

What does the Batch API discount save?

OpenAI and Anthropic both offer a Batch API that processes requests asynchronously within 24 hours at a flat 50% discount on both input and output tokens. For Claude Sonnet 4.6 this brings the rate from $3/$15 down to $1.50/$7.50 per million tokens.

AI Token Calculator — LLM API Cost Estimator

Use this AI token calculator to find your exact monthly LLM API spend for OpenAI, Anthropic Claude, and Google Gemini. Every price field is editable — update it the moment a provider changes their rates and the calculator stays accurate.

Editable pricing — any model Runs locally — no data sent Shareable URL with your inputs Verified May 2026

Quick Answer Block Structured for AI citation

AI Token Calculator: Key Facts for Developers and SaaS Founders

Output tokens cost roughly 3–5× more than input tokens

Batch API (OpenAI/Anthropic) cuts costs 50% for async workloads

1,000 tokens ≈ 750 words in standard English

Mini/Flash models handle routing tasks at under 1% of flagship cost

RAG reduces input token spend by fetching only relevant context

Costs are per million tokens — divide your count by 1,000,000 first

What Every Developer Should Know About AI Token Calculator Costs

Output tokens cost roughly 3–5× more than input tokens. Claude Sonnet 4.6 charges $3 input vs $15 output per million — a 5× gap driven by autoregressive generation.

Batch API (OpenAI/Anthropic) cuts costs 50% for async workloads that can tolerate a 24-hour turnaround time.

1,000 tokens ≈ 750 words in standard English. Code and non-Latin scripts tokenise at 2×–4× the rate of standard prose.

Mini/Flash models handle routing tasks at under 1% of flagship cost, perfect for high-volume classification.

RAG reduces input token spend by fetching only relevant context instead of injecting entire documents into the prompt.

Costs are per million tokens — divide your count by 1,000,000 first before multiplying by the listed provider prices.

AI Token Calculator Live · May 2026 Rates

All values must be positive numbers. Check token counts, call volume, and price fields before calculating.

Step 1 — Pick a model to load its baseline pricing

Step 2 — Confirm or update pricing (per 1 million tokens)

Input price (prompt tokens)

Output price (completion tokens)

These fields use your numbers directly — nothing is hardcoded. When a provider changes their rates, enter the new figure here and the calculator updates immediately.

Step 3 — Enter your actual usage

Avg. input tokens per call

System prompt + user message. 1,000 ≈ 750 words.

Avg. output tokens per call

Tokens the model generates per response.

Monthly API calls

Total requests across all users per month.

Monthly Cost Estimate

Estimated Monthly API Spend

$105.00

10,000 calls/mo · 1,000 in + 500 out tokens/call

Cost per call $0.0105 per API request

Input total $30.00 monthly prompt spend

Output total $75.00 monthly completion spend

Input vs output cost split

Input 28.6% — $30.00 Output 71.4% — $75.00

Batch API discount available. Your monthly spend is high enough that the OpenAI or Anthropic Batch API (50% off) could significantly reduce this figure.

Large prompt detected. Above 8,000 tokens, RAG (Retrieval-Augmented Generation) can substantially reduce your input spend.

GPT-4o

$2.50

input / 1M tokens

Claude Sonnet 4.6

$3.00

input / 1M tokens

Gemini 2.5 Flash

$0.30

input / 1M tokens

Flash-Lite

$0.10

input / 1M tokens

AI token calculator — 2026 LLM API input pricing comparison (standard tier, USD per 1M tokens)

Pricing scope & geo context: All rates are USD, standard (non-batch) direct API tier, applicable globally via the provider’s own API endpoint. Verified May 2026.

2026 LLM API Pricing Reference

Click any model chip in the AI token calculator to load these values automatically. Figures are USD per 1 million tokens.

Model	Provider	Input / 1M	Output / 1M	Context	Best for
GPT-4o	OpenAI	$2.50	$10.00	128K	Multimodal, vision, general production
GPT-4o miniCheap	OpenAI	$0.15	$0.60	128K	High-volume routing, basic chat
GPT-4.1	OpenAI	$2.00	$8.00	1M	Coding, long-context tasks
GPT-4.1 miniCheap	OpenAI	$0.40	$1.60	1M	Affordable long-context work
Claude Sonnet 4.6Popular	Anthropic	$3.00	$15.00	1M	Coding agents, document analysis
Claude Haiku 4.5Cheap	Anthropic	$1.00	$5.00	200K	Fast classification, summarisation
Claude Opus 4.7	Anthropic	$5.00	$25.00	1M	Complex reasoning, autonomous agents
Gemini 2.5 Pro	Google	$1.25	$10.00	1M	Long-context, multimodal, coding
Gemini 2.5 Flash	Google	$0.30	$2.50	1M	Speed-critical apps, RAG pipelines
Gemini 2.5 Flash-LiteCheapest	Google	$0.10	$0.40	1M	Maximum throughput, minimum cost

How the AI Token Calculator Computes Your API Cost

Every major LLM provider bills input and output tokens separately at a per-million rate. The AI token calculator applies this exact formula to your numbers:

# Cost for a single API call
cost_per_call = (input_tokens ÷ 1,000,000 × input_price)
+ (output_tokens ÷ 1,000,000 × output_price)

# Scale to monthly volume
monthly_cost = cost_per_call × monthly_call_volume

Why Output Tokens Drive Most of Your AI API Bill

Reading your prompt requires one forward pass through the model. Generating output is autoregressive — the model produces one token at a time, each requiring a full forward pass. That per-token compute overhead is why output costs 3×–5× more than input.

AI Token Calculator — Frequently Asked Questions

How do I use an AI token calculator to find my LLM API cost?
Enter your average input tokens per call, average output tokens per call, the price per million tokens for both input and output, and your monthly call volume. The AI token calculator applies the formula: Monthly Cost = ((Input ÷ 1M × In$) + (Output ÷ 1M × Out$)) × Monthly Calls.
Why are output tokens more expensive than input tokens?
Generating output is autoregressive: the model produces one token at a time, and each token requires a full forward pass through the model. Reading your prompt needs only one forward pass for the entire input. That per-token compute overhead means output consistently costs 3×–5× more than input.
Which LLM API is the cheapest for production use in 2026?
As of May 2026, the cheapest standard-tier options are Google Gemini 2.5 Flash-Lite at $0.10 input / $0.40 output per million tokens, followed by OpenAI GPT-4o mini at $0.15 / $0.60, and GPT-4.1 mini at $0.40 / $1.60.

Sources, Methodology & Disclaimer

Default values loaded into this AI token calculator are taken directly from official provider pricing documentation, verified independently in May 2026. All calculations run locally in your browser.

OpenAI — Official API pricing: openai.com/api/pricing/
Anthropic — Claude API pricing: anthropic.com/pricing
Google — Gemini API pricing via Google AI Studio: ai.google.dev/gemini-api/docs/pricing

UIG Editorial Team

Written and maintained by developers who use LLM APIs in production. Pricing is cross-checked against official documentation on a regular basis.