size it up.

A little perspective

Trust your eye.

Five comparisons. Two objects each time. How close can you get?

  1. Compare

    The object on the left is your measuring stick. Keep resizing — the view automatically zooms out when you need more room. You can also zoom the canvas; both objects scale together without changing your estimate.

  2. Find the right size

    Drag the blue handle, scroll while hovering it, tap − / +, or use the arrow keys. Match the dimension in the question.

  3. Lock it in

    Reveal the real size and earn up to 100 points. Five rounds add up to a maximum of 500.

The first answer in each round counts. A new challenge arrives every day at 00:00 UTC. Object sizes use the specific examples shown in the answer.

Read the full rules and scoring guide
Practice · not ranked
All past challenges

How long is a tennis court compared with a Concorde?

Use the Concorde as your reference.

01 / 05
Concorde, reference object for length comparison
Tennis court, estimated length relative to the Concorde
ConcordeReference
Tennis courtYour estimate
Fine tune
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View answers and sources

Answers from this past challenge. Today’s challenge remains a surprise.

  1. Round 1

    How long is a tennis court compared with a Concorde?

    Concorde, used for the length comparison
    ReferenceConcorde62.1 m long
    Tennis court, used for the length comparison
    Compared objectTennis court23.77 m long

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 0.3828×

    Tennis court ÷ Concorde, comparing length.

    A tennis court is 78 feet (23.77 metres) long. This silhouette is the doubles court, and the comparison uses that length.

    Measurement source · itftennis.com

  2. Round 2

    How long is a soccer goal compared with an African elephant?

    African elephant, used for the length comparison
    ReferenceAfrican elephant6.5 m long (representative)
    Soccer goal, used for the length comparison
    Compared objectSoccer goal7.32 m wide

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 1.126×

    Soccer goal ÷ African elephant, comparing length.

    The Laws of the Game set the distance between the inside of the posts at 7.32 metres. This silhouette spans that width.

    Measurement source · theifab.com

  3. Round 3

    How long is an American alligator compared with a Komodo dragon?

    Komodo dragon, used for the length comparison
    ReferenceKomodo dragon3.13 m long (verified maximum)
    American alligator, used for the length comparison
    Compared objectAmerican alligator3.4 m long (average adult male)

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 1.086×

    American alligator ÷ Komodo dragon, comparing length.

    Adult male American alligators average about 3.4 metres in length. This round measures the whole animal from its snout to its tail tip.

    Measurement source · nationalzoo.si.edu

  4. Round 4

    How long is a space shuttle compared with a blue whale?

    Blue whale, used for the length comparison
    ReferenceBlue whale33.5 m long (maximum)
    Space shuttle, used for the length comparison
    Compared objectSpace shuttle37.2 m long

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 1.11×

    Space shuttle ÷ Blue whale, comparing length.

    The Space Shuttle orbiter was about 122 feet (37.2 metres) long, measured without its external fuel tank or boosters.

    Measurement source · nasa.gov

  5. Round 5

    How tall is a basketball hoop compared with a giraffe?

    Giraffe, used for the height comparison
    ReferenceGiraffe5.5 m tall
    Basketball hoop, used for the height comparison
    Compared objectBasketball hoop3.05 m high (ring)

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 0.5545×

    Basketball hoop ÷ Giraffe, comparing height.

    The top of a basketball ring is 3,050 mm above the floor. This silhouette is measured to the top of the ring, not the backboard.

    Measurement source · assets.fiba.basketball
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