Free client-side tool
Claude Context Budget Estimator
Paste your instruction and memory files to estimate token cost, startup load behavior, and the point where memory should move into path-scoped rules or on-demand topic files.
Key facts
CLAUDE.md files loaded at launch consume context alongside the conversation.
Auto memory loads the first 200 lines or 25KB of MEMORY.md at session start.
Imported CLAUDE.md files help organization, but they still load into context at launch.
Context estimate
Use the tool
All calculations and files are generated in this page. Nothing is uploaded.
How to use it
Step 1
Paste one or more memory files into the estimator.
Step 2
Choose whether each file is CLAUDE.md, auto-memory MEMORY.md, a rule, or an on-demand topic file.
Step 3
Review estimated tokens, line count, byte size, and startup load status.
Step 4
Trim always-loaded context until only durable, high-signal guidance remains.
FAQ
Is the token count exact?
No. It is an estimate for planning. Tokenization varies by model and content, so treat the result as a budget signal rather than an exact bill.
What context window size should I choose?
Choose the context budget that matches your plan and model when you know it. If you are unsure, use the default as a rough planning baseline.
Why does MEMORY.md show a startup cap?
Claude Code docs say auto memory loads only the first 200 lines or 25KB of MEMORY.md at session start, with topic files read on demand.
Primary Sources
Anthropic Claude Code Docs · Documentation
How Claude remembers your project
Primary reference for CLAUDE.md, auto memory, /memory, file loading, rules, imports, and troubleshooting.
Accessed 2026-07-06
Claude by Anthropic · Blog
Managing context on the Claude Developer Platform
Primary reference for developer-platform memory as a file-based tool managed by the developer.
Accessed 2026-07-06
Related reading
Guides that pair with this tool
Claude-written notes
Claude Code Auto Memory: Storage, Limits, and Audits
How Claude Code auto memory works, where MEMORY.md lives, what loads at session start, and how to audit or clean it.
Read guideInstruction files
CLAUDE.md Guide: What to Put In It and Where
A practical, source-grounded guide to writing CLAUDE.md files for project instructions, local preferences, imports, and AGENTS.md bridges.
Read guideDiagnostics
Claude Memory Troubleshooting
A diagnostic checklist for Claude memory not loading, Claude ignoring CLAUDE.md, stale auto memory, compaction surprises, and project boundary mistakes.
Read guide