Look at the prompt
The object name and category tell you what kind of measurement is being tested. Height is used unless the card says otherwise.
Complete player guide
How to play, read the answer, and get better.
Size It Up is a daily estimating game. See an object, make a size guess in centimeters, lock it in, then use the answer to build a stronger mental ruler.
Example round
A standard door
Move the slider to 176 cm and submit. The real measurement is 200 cm, so the game shows accuracy, points, and a short note that turns the number into a reusable reference.
Start with an anchor
Use a known reference: a door is about 2 m, a counter is about 90 cm, and a basketball rim is 3.05 m.
Move the slider
Drag the handle for big changes. Use the left and right arrow keys for one-centimeter adjustments when you want precision.
Lock in the guess
Click Lock in guess or press Enter. Once submitted, the round switches from guessing to explanation.
Read the reveal
The reveal shows accuracy, points, the actual size, a comparison, a memory anchor, and the measurement basis.
Carry the anchor forward
Use the learned number the next time you see a similar object to estimate faster and with less drift.
Modes
Daily 5 and Explore work differently.
Daily 5 uses the current date to select five objects from the full library. Everyone gets the same daily set, and the set changes automatically tomorrow. Explore mode cycles through the full object bank for practice.
Daily 5Five questions, date-based rotation, final score saved on the page.
ExploreUnlimited practice across the full library.
Skip buttonAdvance to another object whenever you want a fresh prompt.
Practical estimating tips
Use people carefully. Human height is useful, but posture and perspective can trick you.
Convert to door units. For anything taller than a person, ask how many 2 m doors could stack inside it.
Look for category clues. Furniture, appliances, sports objects, animals, and street fixtures follow different size conventions.
Trust the correction. A bad guess is valuable if you remember the anchor it creates.
How to improve
Build a personal reference library.
The fastest way to improve at a size guessing game is to collect a few dependable anchors instead of trying to memorize every answer. Start with the objects you see every day: a phone is around 15 cm tall, a kitchen counter is close to 90 cm, and an interior door is usually near 200 cm. When a new prompt appears, compare it with one of these references before moving the slider.
After each reveal, notice the direction of the error. If you guessed too small, ask whether the object was longer, taller, or wider than the reference you used. That small correction is more useful than the score alone because it gives you a mental rule for the next round.
Small objectsUse a phone, credit card, pencil, or hand-sized item.
Room scaleUse a chair, counter, door, or adult person.
Large scaleStack doors, cars, buses, or street lights in your estimate.
Size It Up FAQ
How do you play Size It Up?
Look at the object, estimate its size in centimeters, move the slider, and lock in your guess. The game then shows the real measurement, accuracy, points, and a useful comparison.
What exactly am I estimating?
The game asks for height in centimeters. For animals, height means shoulder height. For long objects such as rackets, the displayed number is the object's length.
How many rounds are in the daily game?
Daily 5 has five questions. Everyone receives the same date-based set, and the set changes automatically on the next day.
Where do the measurements come from?
Measurements use common residential dimensions, regulation standards, typical appliance sizes, and average object proportions as practical visual anchors.