Observed arrival · 2026-09-29
どれだけいる — “How Much Do I Need?”
A Japanese collection of calculators for estimating how much home-improvement and household material to buy.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Japanese home-center shoppers planning purchases
- Worth noticing
- The operator says figures are checked against manufacturer pages or government materials, not memory alone.
Field notes
The operator says their sales-floor experience is used to identify questions, while published figures are checked against manufacturer pages or government materials. Some entries explain why a familiar shortcut fails: for example, the site says nominal 30 cm tiles can differ in actual size, and overlapping weed-control fabric reduces the width covered. It also draws a safety boundary, declining certain high-consequence calculations.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
$PaidCommerce or pricing visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue