How to Get Better at Size It Up: Judging Size by Eye

How a guess turns into points

Each round is worth up to 100 points. The game does not care how many meters you missed by. It cares how many times too big or too small you were. A guess twice the real size and a guess half of it score exactly the same.

Within 5% of the real size, you get the full 100. At 3 times too big or too small, or worse, you get 0. In between, the score falls in a straight line on a log scale. These are the points you get for a guess that is off by:

• 1.1 times: 96
• 1.2 times: 87
• 1.3 times: 80
• 1.5 times: 66
• 2 times: 39
• 2.5 times: 17

The shape matters. Being 1.3 times off costs you 20 points. Going from 1.3 times off to 2 times off costs about 40 more. So the goal is not to be exact. It is never to be badly wrong.

What a good run of five rounds looks like

A run is five rounds of up to 100 points, so 500 is the top. All five rounds count the same. The last round is worth no more than the first, which means the early rounds deserve as much care as the late ones.

Here is what a steady miss adds up to over a run, with no hints:

• Every guess 1.15 times off: 455
• Every guess 1.3 times off: 400
• Every guess 1.5 times off: 330
• Every guess 2 times off: 195

If your runs sit near 200, the fix is not more trivia. A 2-times miss every round is a calibration problem, and habits fix calibration.

One measurement at a time, never area

Every object is measured one way: height, length, diameter, wingspan, width or span. The name tag under the right-hand object tells you which. A blue whale reads "length", a tower reads "height", a coin reads "diameter".

The game never asks you about area. That removes a whole class of mistakes. You are always comparing one straight line with another straight line, so compare the lines and ignore the bulk of the shape.

Count in multiples of the reference

The object on the left stands at its real size, and its measurement is written under it. That makes it a ruler. Do not think "about 40 meters". Think "about four of these end to end".

The ruler under the picture counts the same way, in times the reference: the labels read ÷8, ÷4, ÷2, ×1, ×2, ×4 and ×8 on Easy, and jump by ÷3, ×3 and ×10 on Medium and Hard. Setting a guess means choosing a multiple, so a multiple is the easiest thing to place. If you can say "about 10 times as big", you have already found the spot on the ruler.

Ten sizes worth memorizing

Estimates get easier when you have a few fixed points. These are sizes as the game states them. They come from the game's own object list, so what you learn here is what you will see.

• US quarter: 2.4 cm across
• Credit card: 8.6 cm wide
• Sheet of A4 paper: 30 cm tall
• Adult man: 1.8 m tall
• Door: 2 m tall
• School bus: 10 m long
• Blue whale: 24 m long
• Statue of Liberty: 93 m tall
• Eiffel Tower: 330 m tall
• Empire State Building: 443 m tall

The values are more useful as ratios. A school bus is about six adult men lying end to end. The Statue of Liberty is about nine school buses. The Eiffel Tower is about three and a half Statues of Liberty, and the Empire State Building is only about a third taller than the Eiffel Tower. Chains like these let you reach a hard object from an easy one.

Why the starting size is never close

The right-hand object always starts at least 1.5 times away from the real size. That is by design, and it has a consequence: if you lock in without moving anything, the best you can score is 66.

So never lock in the starting size, and never treat it as a hint. It is a random point on the ruler, not a clue about the answer. Decide where the object belongs first, then move it there.

Fine-tuning with the keyboard

You can drag the handle on the corner of the object, or slide the ruler. For small corrections, click the picture so it has focus and use the arrow keys. Each press changes the guess by 2%, and Shift with an arrow changes it by 10%. Enter locks the guess in.

Because anything within 5% scores the full 100, the keys give you more precision than you need. Two or three presses are enough to take a guess from "about right" to "inside 5%". Once the two objects look right, lock in. More time on the handle rarely buys points.

What Easy, Medium and Hard ask of you

The levels change how far apart the two objects are and how long the ruler is.

• Easy: the two objects are 1.5 to 6 times apart, and both are measured in the same direction, up and down or side to side. The ruler runs from ÷8 to ×8.
• Medium: 2 to 15 times apart, still measured in the same direction. The ruler runs from ÷20 to ×20.
• Hard: 3 to 30 times apart, and the objects can be measured differently. The ruler runs from ÷40 to ×40.

On Hard, a height can be set against a length. The Statue of Liberty's 93 m height can turn up next to a blue whale's 24 m length, about 3.9 times apart. About half of Hard rounds pair an up-and-down measurement, such as a height or a diameter, with a side-to-side one, such as a length or a wingspan. When that happens, picture the tall thing lying on its side next to the long one.

Hints, bands and their price

Press Hint and the game draws a band on the ruler that holds the real size. There are three hints per round, and the bands get narrower each time: 9 times wide, then 3 times, then 1.5 times. Each band sits inside the one before it.

A hint costs 20 points off the most that round can score. After one hint the cap is 80, after two it is 60, and after three it is 40. That cost only bites if your guess would have scored more than the cap. A guess more than about 1.3 times off already scores under 80, so a first hint is free in that case. The second hint is free for a guess more than about 1.6 times off, and the third for one about 2 times off or worse.

So the rule is simple. When you are unsure by a wide margin, take a hint. When you are within 30%, it costs you points.

One caution: the real size is never placed in the middle of a band. The game puts it off-center, so aiming for the middle is not a plan. Use the band to rule out the ends of the ruler, then use your own sense of size inside it.

Reading the reveal

After you lock in, the right-hand object jumps to its real size and your guess stays behind as a dashed box. A pill shows how far off you were, such as "1.4× too small", or "Within 5%", and the points for the round.

Pay attention to the direction. If most of your misses say "too small", you are shrinking things, and the fix is to push your next guess up. Scoring does not care which way you miss, so the direction is free information about your own bias.

Practice with unlimited runs

Calibration comes from volume. Press Next for a new run of five rounds from a bank of well over a hundred objects, as often as you like. Your best score for each level and your daily streak are kept in the browser, with no account. Only the Daily run counts toward the streak.

If you like estimation, you can guess shelf prices in Costcodle or name countries from their exports in Tradle. For more games in the same spirit, read about daily guessing games like Tradle and Factle. If you prefer pure logic, try how to play Zip. This version of Size It Up is independent and not affiliated with any other size-guessing game, and how our puzzles are made explains where the sizes come from.

A checklist before you lock in

1. Read the name tag. Is it height, length or diameter?
2. Express the guess as a multiple of the reference.
3. Check it against a size you know, as in the list above.
4. Move off the starting size. It is at least 1.5 times wrong.
5. Use the arrow keys for the last few percent.
6. If you cannot narrow the answer below about 1.5 times, take a hint.
7. Lock in. Then read which way you missed.