Translating public domain records into digital utility
An interactive bridge between 19th-century expertise and modern software.
Why look to the past? Because the challenges of space-constrained living, sustainable craft, and analog self-reliance aren't new.
No Cookies. No Tracking.
All calculations happen client-side. Your data never leaves your device.
Verified Sources
Every tool includes citations to original public domain source material.
Lab Cat Certified
Tools include perspective and personality from our resident feline.
From the Lab Cat
πΎ Humans really do enjoy complicating things. Meanwhile, I knock tools off tables and they land perfectly.
The stories behind the tools β history, science, and the curious people who figured it out first
Three Numbers, Sixteen Million Colours
π§ Hex to RGB Converter
Eight Layers Before the First Brushstroke
π§ Gesso Surface Area Calculator
44,100 Snapshots Per Second
π§ Audio File Size Calculator
The President Who Read a Book Before Breakfast
π§ Reading Time Estimator
Two Prices, One Economy, Completely Different Stories
π§ Historical CPI Inflation Calculator
The Light That Lasts Twenty Minutes
π§ Golden Hour Lookup
Each tool includes a bold walkthrough like "π― A Simple Example:" or "π― A Practical Example:" that shows a real scenario step-by-step so you can sanity-check the logic.
Itβs not a generic preview card β itβs a short story with concrete inputs and a clear outcome, right inside the tool where it matters.
π― A Simple Example: Planning a TwoβWeek Project
You have 14 days and a deadline. The example walks through the inputs, shows the computed end date, and explains how to adjust for weekends.
Inputs: Start date + 14 days
Output: Exact end date + total weeks
Seen in many tools, including Date Duration Calculator.
Some of our most fascinating and useful tools
Auto-rotates every few seconds so new favorites surface gently.
Small-batch hits that solve everyday calculations fast
New picks roll in automatically so you can explore at a calmer pace.