How Many Jelly Beans in a Jar? Guessing Calculator
Stop making a wild guess in your competition and use some arithmetic to get a better estimate. Three things drive the estimate: how big the jar is, the size of the candy and how much air is between them. The air gap is where it gets tricky, since sweets tipped into a jar can leave about a third of it empty even though it looks full. Put in your best bet from what you can see and get a better guess:
- Guessing at a fair: eyeball the jar against something you know the size of, then pick a number from the range rather than the exact middle.
- Running the competition: you filled the jar, lost count somewhere past 200, and need a defensible answer to check the winning guess against.
- Buying the sweets: work from the jar that you have so you know how many bags you need to buy to fill it up and have some left over for yourself.
- Not jelly beans: jelly babies, M&M's, Smarties and peanut M&M's all take up different room and settle differently, so the count changes in the same jar.
Estimate the jar
What is in the jar
Jar size
Jar width across
Estimated on the assumption the jar is about half again as tall as it is wide. Type over it if you can measure the jar.
Gap at the top
Regular, about 1.45 cubic centimetres each.
Filled and settled: 34% of the jar is air between the sweets.
Best guess:
455
Jelly beans
Anywhere from 379 if it was loosely tipped in, up to 497 if it was shaken down hard.
Why the air matters more than the sweets
A jar of sweets holds less than it looks like it holds. Tip beans in and they land where they land, leaving gaps that no amount of staring will close. For jelly beans that empty space takes up about a third of the jar. The best that is physically possible is about 72 per cent full for beans and 74 per cent for a round sweet like an M&M, and that is a jar shaken down hard rather than poured. A guess that ignores the gaps comes in high every time.
Shaking the jar changes the answer
Tap a jar on a table and the sweets settle, the gaps shrink, and a few dozen more fit. Between a gently poured jar and one carried around in a car boot there is roughly ten per cent. If you are running the competition, fill and settle the jar once, then leave it alone. If you are guessing, look at whether the surface is loose and uneven or dished and compact.
Frequently Asked Questions
- How many jelly beans fit in a 1 litre jar?
- About 455 regular jelly beans, once you allow for the air between them. A litre holds roughly 660 millilitres of actual sweet, and a regular bean takes up 1.45 cubic centimetres. Smaller gourmet beans can increase the count to around 825, and big classic beans drop it to about 314. The shape of the jar barely matters, only the volume. Convert your jar size between units
- What size is a regular jelly bean?
- A regular supermarket jelly bean weighs about 2 grams and takes up roughly 1.45 cubic centimetres. Gourmet beans are much smaller, at 1.1 grams and 0.8 cubic centimetres, which is why a pound bag holds over 400 of them. Classic jelly beans can be larger, at 2.9 grams or 2.1 cubic centimetres. Convert candy weights between grams and ounces
- Why are jar guesses usually so far out?
- There are two common mistakes when trying to guess the numbers. Working out the volume of the jar and the bean ignores the air gaps, so the guess comes in high, since roughly a third of the jar can be air. The other method is to eyeball it, count beans across, up and through, then multiply the three. It works better than it sounds, but you cannot see the middle, so people guess the depth short and land low.
- Can I use this for M&M's, Smarties or jelly babies?
- Yes. Pick the sweet and the count changes, since each one takes up a different amount of room and settles differently. Flattened sweets like M&M's and Smarties pack closer together than round ones, so a jar of them holds more pieces than the size difference alone would suggest. Jelly babies pack worst, thanks to the arms and legs.
- How do I measure the empty space at the top?
- Estimate the depth of the gap and the width of the jar, by eye if that is all you have. The calculator turns the two into a volume and takes it off before counting. A 3 centimetre gap in a 1 litre jar removes about 210 millilitres, which is a fifth of the jar and roughly 96 beans, so a rough guess beats none.
- What number should I actually write down?
- Take the headline estimate, then look at the range beside it. That range covers the difference between a loosely poured jar and one that has settled hard, and the true count nearly always sits inside it. If the prize goes to the closest guess, the middle number is your best bet. If it goes to the closest without going over, pick the low end.
More conversions
Convert ingredient measurements or fresh fruit and vegetables.
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