★ The founder's workbench
Free tools
for founders.
I kept rebuilding the same calculators for every startup I worked with: what will this cost, how long is our runway, why is the AI bill so high. So I put them here. No login, no email wall.
- 10
- tools
- 0
- sign-ups
- 0
- paywalls
- 1
- engineer
- 01In-browser
MVP Cost Estimator
Pick features and who builds it. Get an hour-by-hour estimate, not an agency teaser.
FeaturesTimelineBreakdown - 02In-browser
LLM API Cost Calculator
Your monthly bill across Claude, GPT, Gemini and open models, side by side.
ClaudeGPTGeminiCaching - 03In-browser
Runway & Burn Calculator
Months of cash left, the date it hits zero, and whether you are default alive.
Burn rateRunwayDefault alive - 04In-browser
SaaS Metrics Calculators
LTV, CAC, churn, NRR, burn multiple and more, each with the formula and benchmarks.
LTVCACNRR12 metrics - 05Live fetch
Meta Tag & OG Preview
See your link on X, LinkedIn, Slack, WhatsApp and Google. Copy the missing tags.
Open GraphTwitter cardNext.js - 06AI
AI Landing Page Roast
Paste your URL. Get roasted on headline, CTA, proof and clarity, then get the rewrites.
AICopyConversion - 07In-browser
Token Counter
Token counts per model, cost per call and how much of the context window you are using.
TokensContextCost - 08In-browser
SAFE & Dilution Calculator
Stack your SAFEs, model the priced round, and see what the founders actually keep.
SAFECap tableDilution - 09In-browser
JSON to Types
Paste JSON, get TypeScript, Zod, Pydantic, Go, Rust, JSON Schema, Prisma or GraphQL.
TypeScriptZodPydantic8 targets - 10In-browser
Cron Expression Builder
Build or explain a cron expression, with the next run times and platform quirks.
CronGitHub ActionsVercel
Coming next
On the bench 🛠️
- Soon
Tech Stack Picker
Six questions about your team and product, one opinionated stack with the reasoning.
Plan & scope
- Soon
Idea → MVP Spec
Describe the idea, get user stories, a must/should/won't list and a 6-week plan.
Plan & scope
- Soon
AI Agent vs Hire
Fully-loaded cost of a hire versus an agent doing the same work, review included.
AI & LLMs
- Soon
Co-founder Equity Split
Weight what matters and get a split both founders can defend.
Money & fundraising
- Soon
Regex Library & Tester
Battle-tested patterns with live tests, explanations and when not to use regex.
Dev utilities
Who made these?
Built by someone who ships
Adopt.ai
Building AI agent features for a US agentic-AI company, from idea to production.
Open-source AI agentCloseLoop
Reconciles payment settlements against bank statements, with the maths kept out of the model.
Full-stack leadPropertyLens
Web and React Native apps on one backend, 2FA auth, deployed on GCP and Vercel.
FAQ?
Fair questions,
straight answers
Are these tools really free?
Do you store what I type?
Where do the numbers come from?
Can you build a custom version for my startup?
Fine print
Tools: on the house.
Engineer: by the hour.
If a tool here just told you something uncomfortable about your budget, runway or AI bill, I can probably fix it.
I'm Himanshu, an AI and full-stack engineer. I build MVPs, AI agents and the growth plumbing around them for early-stage startups.