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 pair of Celestron UpClose G2 10x50 binoculars compared with a pair of Knipex Cobra 87 01 250 pliers?

Use the pair of Knipex Cobra 87 01 250 pliers as your reference.

01 / 05
Knipex Cobra 87 01 250 pliers, reference object for length comparison
Celestron UpClose G2 10x50 binoculars, estimated length relative to the pair of Knipex Cobra 87 01 250 pliers
Knipex Cobra 87 01 250 pliersReference
Celestron UpClose G2 10x50 binocularsYour estimate
Fine tune
All past challenges
View answers and sources

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

  1. Round 1

    How long is a pair of Celestron UpClose G2 10x50 binoculars compared with a pair of Knipex Cobra 87 01 250 pliers?

    Knipex Cobra 87 01 250 pliers, used for the length comparison
    ReferenceKnipex Cobra 87 01 250 pliers25 cm long (nominal)
    Celestron UpClose G2 10x50 binoculars, used for the length comparison
    Compared objectCelestron UpClose G2 10x50 binoculars18.5 cm wide

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 0.74×

    Celestron UpClose G2 10x50 binoculars ÷ Knipex Cobra 87 01 250 pliers, comparing length.

    For Celestron UpClose G2 10x50 binoculars, Celestron specifies 18.5 cm: overall left-to-right width, viewed from above without lens caps or strap.

    Measurement source · celestron.com

  2. Round 2

    How long is a hippopotamus compared with a Black Diamond Circuit crash pad?

    Black Diamond Circuit crash pad, used for the length comparison
    ReferenceBlack Diamond Circuit crash pad121 cm long
    Hippopotamus, used for the length comparison
    Compared objectHippopotamus3.96 m long (large adult)

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 3.275×

    Hippopotamus ÷ Black Diamond Circuit crash pad, comparing length.

    Philadelphia Zoo lists a hippopotamus’s head-and-body length up to about 13 feet, or 3.96 metres. The tail is excluded.

    Measurement source · philadelphiazoo.org

  3. Round 3

    How long is a Brass astrolabe compared with a Telegraph key?

    Telegraph key, used for the length comparison
    ReferenceTelegraph key15.6 cm long
    Brass astrolabe, used for the length comparison
    Compared objectBrass astrolabe15.6 cm diameter

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 1×

    Brass astrolabe ÷ Telegraph key, comparing length.

    For Brass astrolabe, British Museum records 15.6 cm diameter: Outer circular disc diameter of this astrolabe; suspension fittings do not enlarge the horizontal span.

    Measurement source · britishmuseum.org

  4. Round 4

    How long is a JBL Flip 6 speaker compared with a Shure SM58-LC microphone?

    Shure SM58-LC microphone, used for the length comparison
    ReferenceShure SM58-LC microphone16.2 cm long
    JBL Flip 6 speaker, used for the length comparison
    Compared objectJBL Flip 6 speaker17.8 cm long

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 1.099×

    JBL Flip 6 speaker ÷ Shure SM58-LC microphone, comparing length.

    For JBL Flip 6 speaker, JBL specifies 178 mm: horizontal speaker-body width, without the carrying strap.

    Measurement source · jp.jbl.com

  5. Round 5

    How long is a Moleskine Classic Large notebook compared with a Goliath birdeater?

    Goliath birdeater, used for the length comparison
    ReferenceGoliath birdeater28 cm wide (maximum)
    Moleskine Classic Large notebook, used for the length comparison
    Compared objectMoleskine Classic Large notebook21 cm long

    Illustrations shown individually, not to a shared scale.

    Actual size ratio

    ≈ 0.75×

    Moleskine Classic Large notebook ÷ Goliath birdeater, comparing length.

    For Moleskine Classic Large notebook, Moleskine specifies 210 mm: long edge of the closed Large 13 × 21 cm notebook, shown horizontally.

    Measurement source · moleskine.com
All past challengesPlay today’s challenge