What the catalogue records

Every entry has a stable identifier, a category, a measurement in metres, a labelled dimension, a selection note and a source link. The collection contains 158 entries, including 45 countries and territories. Measurements are selected independently. Artwork sources, authors, licences and modifications are listed on the silhouette credits page.

Choosing a value

  • Animals: the note states a zoo’s adult reference or a published upper size. Values are not species-wide averages.
  • Dinosaurs: museum body-length estimates. Reconstructions carry uncertainty.
  • Landmarks: a specified height or length, explicitly including or excluding spires, antennas, pedestals or approaches.
  • Vehicles: a named model and dimension from a manufacturer or operator.
  • Planets and moons: the note distinguishes equatorial, rounded or table diameters. Rings and orbits are excluded.
  • Equipment: a regulated dimension, a chosen value in an allowed range or a labelled conversion from circumference.
  • Countries: approximate map width or height computed from Natural Earth 1:50m outlines on a Lambert azimuthal equal-area projection centred on each country’s longitude/latitude bounds. The longer displayed axis is used, rounded to 1 km. Small coast details are simplified; territorial scope is stated for every entry. Map span is not a surveyed distance or land area.
  • Other geography and nature: maximum published lengths, summit elevations, tree heights or waterfall drops, with their reference stated.

Defined everyday references

The 1.70-metre person is a deliberately chosen reference, not an average. The 80-inch door is another defined example. Neither requires a claim that all people or all doors share those dimensions.

How we draw the scale

Every catalogue entry has its own SVG silhouette. Anatomical poses are illustrative reconstructions; mountain and lake silhouettes are schematic, while countries use geographic boundary data. The labelled dimension is assigned its recorded measurement: body diameter excludes Saturn’s rings, and shoulder height excludes an animal’s head. A single metres-to-pixels scale applies to the reference, guess and answer. Dragging keeps the reference fixed. Zoom and Fit view adjust the camera only; the reveal fits the guess and answer and animates their difference. Portrait thumbnails are not to scale. Map borders follow the source dataset and do not imply a position on disputed claims.

Transparent scoring

Let the error factor be the larger of guess ÷ true size and true size ÷ guess. A factor up to 1.03 scores 100. Otherwise, score = 100 × (1 − log(error factor) ÷ log(4)), rounded and capped at 0–99. Negative results become zero. Thus half and double both score 50. Five rounds total 500.

Daily generation and fair challenges

A fixed catalogue version, the UTC date and the collection produce a deterministic daily set. Friend links include a seed and version, so recipients get the same comparisons. New games use version 2, which includes countries. Version 1 links still reconstruct the original catalogue and selection sequence. An already-started daily stays on its saved version. Sharing a result includes its exact seed, category and version.

Personal stats, not invented rankings

Best scores, completed sets and daily streaks are stored locally. A global percentile would require real, consistently collected player results; none is displayed.

Corrections

Sources can change and better measurements can become available. If a selected value, convention or link is wrong, use the contact form and include the object name, proposed correction and source URL.