The ultimate free AI Cost Calculator for developers, vibe coders, and power users. Instantly estimate API usage costs for top-tier LLMs like Claude 4.6 Opus, Gemini 3.1 Pro, GPT-5.4, and DeepSeek. Whether you need to calculate prompt costs based on manual token estimates, input custom pricing for local models, or use our built-in tokenizer to auto-count tokens directly from your text, this tool prevents API sticker shock. Fast, accurate, and completely free. If you also need to work out percentage increases between model tiers or usage scenarios, our Percentage Calculator is a simple companion.

AI API Cost Calculator

Select AI Model

Estimated Input Tokens

Estimated Output Tokens

Total Estimated Cost:
$0.00

Key Features

Live Token Counter: Paste your exact prompt or AI response to automatically calculate the true token count.
Up-to-Date Pricing: Pre-loaded with the latest API costs for industry-leading models.
Custom Model Support: Running local weights or a niche API? Enter your own custom Input/Output pricing per 1M tokens.
Real-Time Math: Instant cost calculation down to the fraction of a cent.
100% Free & Private: All calculations happen securely in your browser.

How to Use the AI Cost Calculator

Step 1: Select Your AI Model. Choose from our list of popular LLMs in the dropdown menu. If you are using a model that isn’t listed, simply select “Custom Model” to manually enter your specific Input and Output token costs.

Step 2: Enter Your Token Count (Two Ways)

Option A (Manual): If you already know your estimated usage, type the numbers directly into the Input Tokens and Output Tokens fields.
Option B (Auto-Count): Open the “Auto-Count Tokens from Text” section. Paste your system prompt, user query, or the AI’s generated response into the text box. The calculator will instantly read the exact token length. Click Apply to Input or Apply to Output to send the math to the calculator.

Step 3: Get Your Cost Estimate The Total Estimated Cost will update in real-time as you type or adjust your models. If you’re budgeting actual invoice tax on software purchases or digital services, our VAT Calculator can help with the next layer of math.

Step 4: Copy and Share Hit the “Copy Result to Clipboard” button to grab a clean text summary of your projected API cost to drop into your project notes or share with your team. For historical budget comparisons, you may also want our US Adjusted For Inflation Calculator.

Example Use Cases

API budgeting: Estimate the monthly cost of a chatbot, agent, or internal AI workflow before launch.
Prompt optimization: Compare how much different prompt lengths or model tiers affect cost.
Client quoting: Give clients a realistic usage-based estimate for AI features in a product or automation project.

FAQ

Q: Does this tool use live model pricing?
A: It includes current built-in pricing for major models, but you should always double-check provider billing pages for mission-critical estimates.

Q: Can I use custom pricing?
A: Yes. You can enter your own input and output rates for local models, niche APIs, or enterprise contracts.

Q: Does the token counter send my text anywhere?
A: No—this tool is designed to work in your browser for fast private estimates.

You might also find these tools useful:

Percentage Calculator
VAT Calculator
US Adjusted For Inflation Calculator