GeodlyMatch the real-world scale
Geo Size: how to play
Resize countries, US states and landmarks to match their real-world scale. Play five rounds, reveal the true size and score up to 5,000 points.
What is Geo Size?
Geo Size tests your intuition for real-world proportions. A cyan silhouette is your fixed reference. Use the slider below the board to resize the rose silhouette until you think their size relationship is correct.
Area rounds compare countries and US states by total area. Length rounds compare landmark heights with the approximate longer map-axis span of a small country. The prompt always explains which measurement counts.
- Players
- 1 · no account needed
- Rounds
- 5
- Silhouettes
- 22 countries, 10 US states and 2 landmarks
- Maximum score
- 1,000 per round · 5,000 per game
How to play
- 1Read the two names and check whether the round compares area or length.
- 2Move the slider with a finger, mouse or arrow keys to resize the rose silhouette. The cyan reference stays fixed.
- 3Use zoom to inspect both silhouettes at the same magnification. Zoom never changes your answer.
- 4Choose Check size to lock your answer, see the correct outline and reveal the real measurements.
- 5Continue through five rounds, then review your score and choose Play again for a new session.
Scoring
Each round gives up to 1,000 points. A perfect ratio earns 1,000; scores fall linearly with absolute logarithmic error, reaching zero at an eightfold error.
Guessing twice the true size and guessing half the true size earn the same score. Area rounds score area ratios, not width ratios.
Tips
- Twice the area does not mean twice the width. A shape with twice the area is only about 1.41 times larger along each axis.
- Landmark length rounds are not area questions. Everest is measured above sea level, and the Empire State Building includes its antenna.
- Geographic length is a rounded educational map span, not an official surveyed diameter. Wider outlines are rotated upright for the comparison.
What you learn
Explore the relative areas of countries and US states, and compare tiny countries with familiar landmarks. All boundaries load locally; equal-area projection and normalization keep area comparisons consistent.
Questions and answers
- Does the slider change both shapes?
- No. Only the rose silhouette changes size. Zoom changes both together and does not alter your guess.
- Are height and area mixed?
- No. Every round is either an area comparison or a clearly labelled length comparison, with separate definitions and scoring.
- Which landmark heights are used?
- Empire State Building is 443.2 metres including the antenna. Mount Everest is 8,848.86 metres above sea level. Landmark outlines are stylized illustrations.