LLM cost per user calculator for SaaS products

Enter your token usage, model choice, and MAU — see blended cost per user, per-tier breakdowns, and what happens when you 10x. Built for founders who need a number, not a spreadsheet.

·Per-user LLM cost across GPT-4o, Claude Sonnet/Opus, Gemini, and open-source — priced live.
·Split by prompt tokens vs. completion tokens so you see where the bill actually comes from.
·Project cost at 1K, 10K, and 100K MAU without rebuilding the sheet every time.

Founders use this before every pricing change, investor update, and model migration.

Model & Usage

Which model does your app use?

AI calls per active user per day: 5

Avg input tokens

Avg output tokens

Days active per month: 20

Not everyone uses it daily — default 20 is realistic

≈ $0.011500 per call · $1.15 per user/month · $1,150/mo at 1,000 users

Scale

Current MAU: 1,000

MAU target (6 months)

Used to show projected future cost

What do you charge per user? ($)

Used to show danger zone in chart

Compare with:

Cost Per Active User

$1.1500

Based on 5 calls/day × 20 active days/mo

Total Monthly AI Bill

$1,150

1,000 users × $1.1500

Projected at 10,000 MAU

$11,500

At your 10,000 MAU target

AI Cost Scaling

openai/gpt-5.5

Model Comparison

Model	Input $/M	Output $/M	CPAU?	Monthly @ 1,000	vs. Current
OpenAI: GPT-5.5current	$5.00	$30.00	$1.1500	$1,150	—
OpenAI: GPT Chat Latest	$5.00	$30.00	$1.1500	$1,150	+$0/mo
Anthropic: Claude Opus 4.8	$5.00	$25.00	$1.0000	$1,000	Save $150/mo
Anthropic: Claude Opus 4.7	$5.00	$25.00	$1.0000	$1,000	Save $150/mo
Anthropic: Claude Opus 4.6	$5.00	$25.00	$1.0000	$1,000	Save $150/mo

Insight

At your current usage pattern (5 calls/day, 500 input + 300 output tokens each), each user costs $1.1500/month in OpenAI: GPT-5.5 API fees. Switching to Anthropic: Claude Opus 4.8 would drop that to $1.0000/user/month — saving $150/month at 1,000 MAU, or $1,500/month at 10,000 MAU.

Prices sourced from OpenRouter and updated automatically. Always verify with your provider before making pricing decisions. Estimates do not include volume discounts or enterprise rate cards.

This LLM cost per user calculator gives SaaS founders a straight answer to one of the hardest questions in AI pricing: how much does one active user really cost per month? It handles GPT-4o, Claude, Gemini, and custom token pricing, and it scales cleanly from 100 MAU to 100,000. If you've been patching together a ChatGPT API cost calculator out of spreadsheets and Reddit math, replace it with this.