About SizeItUp

SizeItUp is a free daily game about your sense of scale. Each round puts a familiar object at true scale beside an orange silhouette. You resize the silhouette until the pair looks true to life, lock in, and see how close you got. Five rounds a day, a few minutes each morning.

How it works

• The teal object is the reference. It is drawn at its real size and never changes.
• Drag the corner handle, pinch, or use the arrow keys to resize the orange silhouette.
• Lock in to reveal the true size, a fact about the object and a link to where the number comes from.

The daily games

• Classic: everyday objects, from a credit card to the Eiffel Tower.
• Cosmic Scale: planets, moons, stars, mountains and spacecraft.
• Prehistoric Giants: dinosaurs and extinct giants beside today's animals.

Each game has its own puzzle and its own daily leaderboard. Kitchen Table and Tiny Worlds are on the way.

Where the sizes come from

Every answer names what is measured (a planet's equatorial diameter, an elephant's shoulder height, a skeleton's length) and links to its source. Cosmic Scale uses NASA fact sheets, JPL and published papers. Prehistoric Giants uses museum specimens and peer-reviewed studies; sizes of extinct animals are estimates, and where a source gives a range we use its midpoint and say so. Classic's measurements are sample content still being checked against primary sources.

Spotted a number that looks wrong? Tell us at support@sizeitup.us with the object and a source, and we'll check it.

Scoring and fair play

A round scores up to 100 points. What counts is the ratio between your guess and the truth, so guessing double is as far off as guessing half. Within 6% scores all 100; twice or half the size scores about 33; five times off scores 0.

Scores are worked out on our server, and the puzzle files your browser downloads never contain the answers. Signed-in players get one ranked attempt per round, which is what the leaderboard counts. Ranked play also earns Insight, which you can spend on titles and board themes. There are no ads and nothing to buy with money.

Who makes it

SizeItUp is made by Immortal Reality PA LLC in Pittsburgh, Pennsylvania. Find us at immortalus.ai, or see the contact page.