Know your AI costs
before you build.
Real pricing. 30+ models. No guessing. From token calculators to agent cost estimators — NumStack gives you the numbers you need to build confidently.
11 Calculators. All Free.
9 AI/LLM tools + 2 financial calculators. No signup required.
Token Cost Calculator
Calculate and compare AI API costs across 30+ models. Input your usage pattern, see monthly projections.
Model Selector
Tell us your use case, budget, and requirements. Get the top 3 AI models ranked for your situation with cost estimates and rationale.
Agent Cost Calculator
Estimate true costs for multi-step AI workflows. Accounts for tool calls, retries, and context growth.
Prompt Optimizer
Reduce token usage without losing quality. Get 3 optimized variants with before/after comparison and monthly savings estimate.
Chatbot Cost at Scale
How much will your customer-facing chatbot cost at scale? Inference, hosting, vector DB, monitoring, and ROI vs human support.
Agent Workflow Calculator
Model multi-step LLM pipelines stage by stage. Add up to 10 steps, pick models per step, and see total cost with swap scenarios.
Fine-Tuning ROI
Fine-tune, prompt engineer, or build RAG? Data-driven break-even analysis with cost projections across all three approaches.
Latency & Throughput
Set your RPS target and latency SLA — get instance recommendations, p50/p95/p99 estimates, and AWS vs GCP cost comparison.
Vector DB Cost
Compare Pinecone, Weaviate, Qdrant, Supabase, and Chroma side-by-side. One-time embedding cost + monthly storage + query breakdown.
Paycheck Calculator
See exactly how much you take home after taxes. Supports all 50 states with accurate federal and state rates.
Tax Refund Calculator
Estimate your tax refund or amount owed. Includes deductions, dependents, credits, and capital gains for 2026.
30+
AI Models
9
AI Calculators
$0
To start
100%
Real pricing
Built for people who build with AI
Everyone from solo hackers to finance teams uses NumStack.
Solo Builders
Know your AI spend before you launch. Don't get surprised by a $500 API bill on your first product.
Engineering Teams
Compare models to find the best cost/performance ratio for your specific token usage patterns.
Finance & Ops
Get budget-ready cost projections with daily, monthly, and annual breakdowns per model.
API Integrators
Automate cost tracking in your CI/CD pipeline using the NumStack REST API.
Use it in your code
The NumStack API lets you calculate costs programmatically. Free tier is 10 calls/day — no key required. Pro is $4/month for 1,000 calls/day.
curl -X POST https://numstack.net/api/calculators/token-cost \
-H "Content-Type: application/json" \
-d '{
"model": "gpt-4o",
"inputTokens": 1000,
"outputTokens": 500,
"requestsPerDay": 100
}'
# Response → monthly cost: $22.50Stop guessing. Start knowing.
Free to use. No signup required. Real pricing from official sources.
Calculate Your AI Costs — Free →