AI API Cost Calculator: Compare GPT, Claude, Gemini & Grok

A privacy-first planning tool for developers and serious AI users · Updated September 1, 2026

API pricing looks simple until input tokens, output tokens, cached context, and request volume start multiplying. Use this page to estimate a realistic monthly cost before choosing a model or committing to a provider.

The short answer

Use Token counter for a quick, local estimate of a prompt’s input size.
Use Monthly API cost when you know your average prompt, response length, and monthly request count.
Use Subscription vs API when you want to compare metered usage with a fixed monthly plan.
These are planning estimates. Confirm the provider’s current pricing, limits, taxes, and product terms before spending money.

HiseHub AI Cost Lab

Estimate AI API costs before the bill arrives

Count a prompt locally, model a monthly workload, and compare GPT, Claude, Gemini, and Grok API costs. The calculator is an estimate—not a provider invoice—and it never asks for an API key.

Model Input tokens / request Output tokens / request Requests / month Cached input share

Use average tokens, not characters. If the selected model has no published cache rate, the cache field is ignored and the result says so.

Paste a prompt or text (processed in this browser)

Model for a one-request estimate Expected output tokens

Model Input tokens / request Output tokens / request Requests / month Subscription price / month

Cached input share

This compares metered API spend with a fixed subscription price. A subscription’s usage caps, included features, and product licensing still need a separate check.

How to use this estimate

Useful for planning, not for pretending every provider bills the same way

Input and output prices are separate. Long answers can cost much more than short ones even when the prompt is unchanged.
Cache estimates are optional. Enter the share of input tokens served from cache only when the provider and model publish a cache rate.
Token counts vary by tokenizer. The browser counter is deliberately labelled an estimate; use the provider’s own token endpoint for a production invoice check.
Tools and special tiers can add cost. Batch, priority, reasoning, image, video, and server-side tool charges may not be represented in a simple text estimate.

Model rows are served from HiseHub’s server-side comparison cache and show the last synchronization time (September 9, 2026 06:36 UTC). Verify final rates at OpenAI, Anthropic, Google, or xAI before committing to a budget.

Need the consumer-plan side? Compare AI subscription prices by country, use the AI Plan Finder, or review AI model capability and value.

Why API cost is harder than a single price per million tokens

Most providers publish separate rates for input and output tokens. A request that sends a long system prompt and receives a short answer has a different cost profile from a short question that produces a long explanation. In a chat application, the conversation history can also be sent again on every turn, so the amount of input grows even when the user’s latest message is small.

Some providers add more dimensions. Prompt caching can reduce the price of repeated context, while batch processing trades immediate responses for a discount. Reasoning tokens, image or video input, server-side search, and other tools may be billed separately or counted differently. A useful calculator therefore needs to show its assumptions instead of presenting one false “exact” number.

How the monthly estimate works

For a text-only request, the basic calculation is:

input cost  = input tokens × input price ÷ 1,000,000
output cost = output tokens × output price ÷ 1,000,000
monthly cost = (input cost + output cost) × requests per month

If you enter a cached-input share and the model has a cached-input rate in the current data, the tool applies that lower rate to the selected share of input tokens. It does not assume that all context is cacheable, and it does not hide a missing cache rate behind a guessed discount.

What the result does—and does not—tell you

It does: turn a workload assumption into a comparable per-request and monthly estimate across representative GPT, Claude, Gemini, and Grok models.
It does: show a break-even request volume when a fixed subscription price is compared with the selected API workload.
It does not: promise that a consumer subscription includes API credits. Chat products and developer billing are normally separate.
It does not: account for every provider-specific fee, tax, quota, retry, tool call, rate-limit error, or application hosting cost.
It does not: measure answer quality. Use the AI Model Comparison for capability, speed, and benchmark context.

How to estimate your own workload without guessing wildly

Take a representative week of requests rather than using your busiest day.
Separate the reusable system prompt or reference context from the user’s changing message.
Measure typical output length; a long answer can cost several times more than a short answer on the same model.
Multiply by actual monthly requests, including automated retries and scheduled jobs.
Run a low, typical, and high scenario. The high scenario is more useful for setting a spending alert than a single optimistic average.

For a production service, compare the estimate with the usage fields returned by your provider’s SDK or API. That real usage should become your source of truth after launch; this page is a planning aid before and between deployments.

API or subscription: which route fits?

A subscription is usually easier for a person who wants a finished interface, file uploads, memory, voice, or a predictable monthly charge. An API is the correct route for an application, automation, or service that sends requests on behalf of multiple users. The cheapest option depends on workload, not only the headline price.

The calculator’s break-even result is only one input to that decision. Check whether the subscription’s usage caps fit your work, whether the product terms allow your intended use, and whether the API needs extra hosting, logging, retrieval, or moderation costs. When the result is close, a hybrid setup—a personal subscription plus API billing for a product—may be more practical than forcing one route to do both jobs.

For the decision behind the math, read AI Subscription vs API: Which Is Cheaper for Your Actual Usage? and compare its guidance with your own workload.

Privacy and data handling

The token counter estimates text in your browser. HiseHub does not ask you to paste an OpenAI, Anthropic, Google, or xAI API key, and the calculator does not need to upload your prompt to calculate the displayed estimate. Do not paste secrets, personal records, or confidential customer data into any online tool unless you have reviewed its data handling first.

Official references

OpenAI tiktoken — the official open-source tokenizer used with OpenAI models.
Anthropic Count tokens in a Message — counts message input including supported tools, images, and documents.
Google Gemini countTokens API — documents token counting for text and supported media inputs.
xAI API pricing — lists model rates and special pricing such as cached, batch, and priority processing.

HiseHub is an independent reference site, not an affiliate or representative of OpenAI, Anthropic, Google, xAI, or X. Provider prices, model names, limits, and terms can change. The calculator uses the latest server-side comparison data available to HiseHub and labels its output as an estimate.

Continue planning your AI setup

Compare model capability and value, check consumer subscription prices by country, or use the AI Plan Finder when you are choosing a paid chat plan. If a paid entitlement is missing, start with the AI Subscription Troubleshooter rather than buying a second plan.

If the API estimate is part of a larger system, compare local runtimes, chat interfaces, and workflow platforms in the Self-Hosted AI Tools directory before adding hosting and maintenance costs.

AI API Cost Calculator & Token Counter