Observed arrival · 2026-10-01
CalcVisual: calculators that show their work
A collection of 54 visual calculators for tasks ranging from aquarium setup and off-grid power to surf sizing and economics.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Aquarium keepers, off-grid planners, and economics students
- Worth noticing
- The sample aquarium result separates nominal tank capacity (57 gallons) from estimated actual water (46 gallons).
Field notes
The homepage organizes 54 calculators across six areas, with individual links for tasks such as pool heating costs, battery runtime, and wetsuit thickness. Its aquarium example distinguishes nominal tank capacity from actual water volume and names Aqueon and the National Institute of Standards and Technology among its references. The site says its formulas are checked against two published sources; that verification claim is presented by the project itself.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue