free_tools
Tools I built to think with
Free, no sign-up. The same back-of-the-envelope models I use on real engagements — made interactive so you can run your own numbers.
AI Agent Cost Calculator
Estimate the monthly cost of an LLM agent across Claude, GPT-4o and Gemini — including the agentic context tax most calculators miss.
Open toolreliability · sloSLO & Error Budget Calculator
Turn an availability target into the downtime it really permits, a request error budget, and the burn rate that says when to stop shipping and fix reliability.
Open toolreliability · costDowntime Cost Calculator
Put a dollar figure on downtime: what an hour offline costs, your annual exposure, and what each additional 'nine' of availability is actually worth.
Open toolcapacity · scalingThroughput & Concurrency Calculator
Little's Law capacity planning: turn requests/second and latency into the concurrency you must support and the number of instances to serve it with headroom.
Open toolperformance · latencyLatency Budget Calculator
Set an end-to-end p95 target and carve it across the hops a request takes — network, app, database, cache — to see where the budget goes and what to fix first.
Open toolaudit · 2 minProduction-Readiness Scorecard
A 2-minute assessment across reliability, security, cost, scale and AI readiness — with a score and a prioritized list of what to fix first.
Open tool