The toolkit · 5 live
Tools you actually open.
Single-file, browser-based financial tools for the period between first paying customer and Series A. We ship one every other week. No signup. Works offline. Saves locally. Drop your email below to hear about the next one.
Live
01 · Live
↗Solo Founder Runway Calculator
Cash, MRR, burn, growth, planned hires. See exactly when you run out — and the cost of each hire on your timeline.
runway, cash, hire impact
02 · Live
↗MRR Health Snapshot
Quick Ratio, NRR, gross churn. One A–F grade. The same numbers Series A diligence opens with.
MRR, quick ratio, NRR, churn
03 · Live
↗CAC Payback Calculator
Payback months, LTV:CAC ratio, gross-margin adjusted. The verdict every paid-channel decision sits on.
CAC, LTV, payback, channels
04 · Live
↗Cohort Visualizer
Retention curves, heatmap, leak-month detection, cohort-based LTV that flat-churn estimates always overstate.
cohort, retention, LTV, churn curves
05 · Live
↗Fundability Scorecard
Five inputs. One radar chart. Pre-seed / Seed / Series A band, weakest pillar, and the question every investor leads with.
fundability, raise, NRR, runway
How it works
No signup. No login. No data leaves your browser.
Every tool is a single HTML page running vanilla JavaScript in your browser. Inputs save to local storage on your device — close the tab, come back next week, your numbers are still there.
No account creation. No telemetry. No data sent to a server. Export to PDF when you need to ship the result to your investor or co-founder.
The same way you'd use a calculator app — but built around the metric you actually care about.
Stay in the loop
Get the next tool the day it ships.
One email per tool. Plus the field notes behind the build — what we tested, what we threw out, the math that didn't survive contact with real customers.