1/3 Cup Blueberries in Grams
1/3 cup of blueberries weighs about 56.7 g (spooned and levelled, King Arthur Baking). That is 170 g per cup divided by three. The short answer is at the top, and the rest of this page explains how that number was worked out, when it matters, and what to watch out for when you use it.
Blueberries is described in the data as follows: Small, sweet blue berries. It is used for muffins, pancakes, salads and snacking. Knowing the weight matters because recipes written in cups assume a particular way of filling the cup, and that assumption is invisible until a bake comes out wrong. A cup of a light, airy ingredient can weigh much less than a cup of a dense one, so converting by volume alone tells you nothing about how much of the ingredient is actually in the bowl. Weighing 56.7 g of blueberries removes that guesswork, and it makes the recipe repeatable: the same weight gives the same result next week, in a different kitchen, with a different set of cups.
The one-third cup is a particularly useful measure because it sits at the centre of the usual scaling steps. Halve two-thirds of a cup and you get one-third. Double one-third and you get two-thirds. Add one-third to two-thirds and you have a full cup. Recipes written for two people, test batches, and scaled-down bakes use it constantly, which is why it deserves its own page rather than a passing mention in a table.
Conversion table for blueberries
| Amount | Grams (approx.) |
|---|---|
| 1/4 cup | 42.5 g |
| 1/3 cup | 56.7 g |
| 1/2 cup | 85 g |
| 2/3 cup | 113.3 g |
| 3/4 cup | 127.5 g |
| 1 cup | 170 g |
| 1 1/3 cups | 226.7 g |
| 2 cups | 340 g |
Every figure in this table is calculated from the same base value — 170 g per cup, spooned and levelled, from King Arthur Baking — multiplied or divided by the fraction shown. No other source was used, and no figure was guessed. If you need an amount that is not in the table, divide 170 g by the denominator of your fraction, or multiply 56.7 g by the number of third-cups you need: three third-cups make a cup, so three lots of 56.7 g should add up to about 170 g, which is a useful check that your arithmetic and your scale agree.
How to measure one-third of a cup of blueberries
A cup is a volume, and grams are a weight, so every conversion on this page depends on how the cup was filled. The method given in the data is the method you should copy. The reference method for blueberries is spooned and levelled. For a dry ingredient that means spooning it into the measure and levelling the top with the back of a knife, rather than scooping the cup through the bag, which packs it down and adds weight. For a poured ingredient it means pouring to the line and reading the level at eye level. For a scooped ingredient it means pressing it into the measure so there are no air pockets. Copying the method is what makes the 56.7 g figure true; changing the method changes the weight, sometimes by a lot.
A kitchen scale is the simplest way to get this right. Put a bowl on the scale, press tare to zero it, and add blueberries until the display reads 56.7 g. That is the whole technique, and it takes less time than finding the right measuring cup. If you do not have a scale, use a proper one-third cup measure rather than estimating a third of a larger cup, and level it carefully. Shaking the cup to settle the contents, tapping it on the bench, or heaping it above the rim all change the weight, and with a light ingredient those changes are a large share of the total.
The most common mistake is treating all cups as equal. A US cup is the standard used throughout this page and in the King Arthur Baking data, and it is the cup most English-language recipes mean. If your recipe comes from a country that uses metric cups or imperial measures, check which cup it means before converting, because a different cup size changes every figure on this page. The second most common mistake is measuring a dry ingredient in a liquid jug or a liquid in a dry cup: the two are designed differently, and using the wrong one adds a systematic error to every measurement.
Worked examples
A recipe that needs two-thirds of a cup
Picture a recipe calling for two-thirds of a cup of blueberries. That is two lots of one-third of a cup, so about 113.3 g. Weighing it in two lots of 56.7 g is easier than weighing 113.3 g in one go, because you can tare the scale between lots and catch a mistake early. This is the approach to use for a spice blend, a tray of roasted nuts, or a batch of cookies where blueberries is a headline ingredient: the weight is the same every time, where a cup of a light, airy ingredient can vary by a fifth depending on how it was poured and whether it was shaken down first.
Halving a recipe that needs two-thirds of a cup
Halving is where the one-third cup measure earns its keep. A recipe for a full tray that needs two-thirds of a cup of blueberries becomes 56.7 g when you halve it for a smaller tray or a test batch. Weigh the 56.7 g, and if the recipe also halves other ingredients, weigh those too rather than halving by eye — small errors add up when every ingredient is halved approximately. A test batch weighed properly tells you the truth about a recipe; a test batch guessed at tells you nothing, because you cannot tell whether the result came from the recipe or from your measuring.
Scaling up to one and one-third cups
Scaling up is the mirror image. A recipe that serves four with one-third of a cup of blueberries serves sixteen with one and one-third cups, about 226.7 g. That is four lots of 56.7 g, and weighing it in four equal lots on a tared scale is more accurate than filling a cup four times and hoping each fill matches the last. If you are scaling up for a gathering or a bake sale, write the gram totals on the recipe card as you go: 56.7 g per third-cup, 113.3 g per two-thirds, 226.7 g per one and one-third cups. Next time you will not need to do the arithmetic again.
Method, source, and why the figure is approximate
The base figure for blueberries is 170 g per cup, measured spooned and levelled and sourced from King Arthur Baking. That pairing of method and source is the whole basis of this page: the weight only means something when you know how the cup was filled and who measured it. A cup of blueberries that is scooped, packed, sifted, or shaken will weigh something different, and a source that rounds its figures will give a slightly different number from one that does not.
There is a note on this figure in the data worth knowing. King Arthur gives a range of 140-170 g per cup for fresh blueberries; we use the top of the range, 170 g. That is why the 56.7 g figure on this page is labelled approximate rather than exact, and why weighing with a scale beats converting from cups whenever the recipe is sensitive.
All density-based results on this page are labelled approximate, and they should be treated that way. The honest way to use them is as a starting point for everyday cooking and as a precise-enough guide for most baking, with a kitchen scale as the final check whenever the result matters — a cake for a celebration, a loaf you are selling, a batch you are preserving, or any recipe you plan to repeat. If your own weighing disagrees with the table by a gram or two, trust your scale: it is measuring your ingredient, in your kitchen, today.
It is also worth knowing what this page does not do. It does not claim that every brand of blueberries weighs exactly 170 g per cup, because brands differ in grind, moisture, and packing. It does not convert other ingredients, and it does not invent a figure for an ingredient that is not in the data. If you need a different ingredient, use its own page, where the same method and the same source discipline apply.
Practical guidance: when this conversion matters most
This conversion matters most when blueberries is doing structural work in a recipe rather than just adding flavour. In baking, the ratio of dry ingredients to liquid decides whether a cake rises and sets or sinks and stays wet in the middle, and a third of a cup is a large enough amount for a measuring error to change that ratio. In a spice blend or a seasoning mix, the same third of a cup may be the difference between a dish that is balanced and one that is dominated by a single flavour. In batch cooking, small errors multiply: if you are off by a few grams per third-cup and you use four third-cups, the error is four times as large.
When you do not have a scale, the best fallback is to measure carefully with cups and to keep the rest of the recipe consistent: if you measured blueberries by volume, measure the other dry ingredients by volume too, rather than mixing weighed and cup-measured ingredients in the same bowl. Mixing methods mixes two different kinds of error, and the result is harder to diagnose when something goes wrong. If a bake fails and you measured by volume, the first thing to check is whether the cup was filled the way the recipe assumed — spooned and levelled, packed, or poured — because that is the most common cause of a dry or wet crumb.
A practical habit that costs nothing is to write the gram weight on the recipe the first time you weigh an ingredient. Next time you will not need this page at all for that recipe, and you will have a record of what actually worked in your kitchen. Over time those notes become a personal conversion table that is more accurate for your brands and your equipment than any published table, because it was measured where you cook.
Storage and uses
Refrigerate unwashed; use within 1 week. Blueberries is used for muffins, pancakes, salads and snacking. Storage matters for conversion accuracy as well as for freshness: an ingredient that has absorbed moisture from the air weighs more per cup than a dry one, and one that has dried out weighs less. Keeping blueberries in the conditions described in the storage notes — an airtight container, in the right place, for no longer than the keeping time — keeps its weight per cup close to the published figure, which keeps this page accurate for you. If a packet has been open for months in a humid kitchen, weigh it rather than trusting the cup, and replace it if it smells stale, has clumped hard, or shows any sign of spoilage.
Frequently asked questions
How many grams is 1/3 cup of blueberries?
About 56.7 g, spooned and levelled, according to King Arthur Baking. That comes from 170 g per cup divided by three. The figure is approximate — blueberries varies a little by brand, grind, and moisture — so verify with a kitchen scale when the amount matters, for example in baking or when you are scaling a recipe.
Is 56.7 g exact?
No. It is an approximate conversion. A cup measures volume and a gram measures weight, so the true weight of one-third of a cup of blueberries depends on how it was measured, how settled it is, and its moisture content. The 170 g per cup figure from King Arthur Baking is the best available reference, and 56.7 g is that figure divided by three. For everyday cooking the approximation is fine; for precise baking, weigh the ingredient and trust the scale.
How do I measure 1/3 cup of blueberries without a scale?
Use a one-third cup measure if you have one, and fill it the way the data specifies: spooned and levelled. If you only have a one-cup measure, fill it to the one-third mark, or fill a half-cup measure two-thirds full — though that is harder to judge by eye. Level the top with a straight edge for dry ingredients, and read liquids at eye level. A scale is more accurate, and a basic kitchen scale costs less than a set of measuring cups.
How many grams is 2/3 cup of blueberries?
About 113.3 g — double the one-third cup figure of 56.7 g. Two-thirds of a cup is the amount that appears most often alongside one-third of a cup in recipes, because halving two-thirds gives one-third and doubling one-third gives two-thirds. Weigh it as two lots of 56.7 g if you want to check your work as you go.
Can I use this conversion for a different brand of blueberries?
Yes, as a starting point, but expect small differences. Different brands grind, dry, and pack blueberries slightly differently, and those differences change how much fits in a cup. The King Arthur Baking figure of 170 g per cup is a representative value, not a guarantee for every packet. If a recipe is sensitive — a cake, a loaf, or a preserved batch — weigh your own brand once and note the result for next time.