1 cup is 2.89 ounces of ground coffee. Below is the full chart, with a section of its own for each amount worth having to hand.
Cups to ounces: full chart
| Cups | Ounces |
|---|---|
| 1/4 cup | 0.723 oz |
| 1/2 cup | 1.45 oz |
| 1 cup | 2.89 oz |
| 2 cups | 5.78 oz |
| 3 cups | 8.68 oz |
| 4 cups | 11.6 oz |
| 6 cups | 17.4 oz |
| 8 cups | 23.1 oz |
| 12 cups | 34.7 oz |
| 16 cups | 46.3 oz |
Where this conversion shows up in practice
1 cup is 2.89 ounces of ground coffee. 1 of these makes 2.89, counting from the 1 cup figure of 2.89 ounces. 2 cups is 5.78 ounces of ground coffee. 2 of these makes 5.78, counting from the 1 cup figure of 2.89 ounces. 4 cups is 11.6 ounces of ground coffee.
Half this amount, 2 cups, comes to 5.78; double it and you are at 23.1. 8 cups is 23.1 ounces of ground coffee. Half this amount, 4 cups, comes to 11.6; double it and you are at 46.3.
The quick version
To go from cups to ounces, multiply by about 2.89. One cup is 2.89 ounces. The arithmetic does not change with the amount you start from. Going back the other way, one ounce returns 0.346 cup.
No weighing is involved, so there is nothing to get wrong at the scale.
Worked through, start to finish
Say a batch you are making for a crowd asks for 6 cups, and your equipment is only marked in ounces. Take the one-cup figure of 2.89 ounces and apply it 6 times: 17.4 ounces. That is the number you want on the jug.
Swap the coffee for something else and the figure moves.
Why this one depends on the ingredient
Two cups of equal size can differ in weight by half again, because a cup measures space. ground coffee comes in at 82 g a cup against 237 g for water — 65 per cent lighter — and the chart is that figure scaled.
Put the other way round, a pound of ground coffee fills 5.53 cups, and 5.13 g of it comes to a level tablespoon. Neither number transfers to a different ingredient.
Weight per cup for common ingredients
| Ingredient | 1 cup weighs | 1 pound gives |
|---|---|---|
| Ground coffee | 82 g (2.89 oz) | 5.53 cups |
| Rolled oats | 89 g (3.14 oz) | 5.1 cups |
| Cocoa powder | 85 g (3 oz) | 5.34 cups |
| Honey | 340 g (12 oz) | 1.33 cups |
| Water | 237 g (8.35 oz) | 1.92 cups |
| All-purpose flour | 120 g (4.23 oz) | 3.78 cups |
Every figure above is one level cup, spooned in and swept flat. Scooping straight from the bag packs the cup and can add a fifth again to the weight, which is why bakers who want the same result twice weigh instead of measuring.
How the chart works
Work from the row nearest your amount and adjust from there. The step between neighbouring rows is small enough that eyeballing the gap is safe.
What moves this number
How long the bag has been open. Anything that draws moisture from the air gains weight sitting on the shelf, and gains it unevenly.
Anything that changes how the ingredient sits in the measure changes the answer with it.
Going the other way: ounces to cups
| Ounces | Cups |
|---|---|
| 1/4 oz | 0.086 cup |
| 1/2 oz | 0.173 cup |
| 1 oz | 0.346 cup |
Measuring it properly
The packing problem is why two cooks measuring “one cup” of the same ingredient can be twenty per cent apart. A scale sidesteps it.
The same cup of the same ingredient can vary by a fifth depending only on how it got into the cup. Nothing about the ingredient changed; only the air trapped in it did.
When you can round and when you cannot
A convenient number costs little on a single quantity and adds up quickly once a recipe is doubled or tripled. Round late, not early.
Where a recipe gives an odd figure it usually got there by conversion rather than by choice. Rounding it back to the round number it started as is often closer to the intent than the decimal.
The error people make most often
Packing the cup without meaning to. Dipping the cup into the bag is the natural motion and the one that adds the most weight; spooning in and levelling is the measure every recipe assumes.
Where this comes up
Most recipes are written for one system and cooked in another. American recipes measure by cup, European ones by gram, and anything from a bakery measures by weight. Knowing that 1 cup is 2.89 ounces is what lets you cook from any of them.
Packaging, recipes and kitchen equipment rarely agree on units. 1 cup is 2.89 ounces — the figure to keep in mind when they disagree.
Spoon and part-cup weights
| Measure | Ground coffee | In ounces |
|---|---|---|
| A quarter cup | 20.5 g | 0.723 oz |
| A third of a cup | 27.3 g | 0.964 oz |
| Half a cup | 41 g | 1.45 oz |
| Two thirds of a cup | 54.7 g | 1.93 oz |
| Three quarters of a cup | 61.5 g | 2.17 oz |
| One cup | 82 g | 2.89 oz |
Below roughly 3 g a spoon beats a scale, because that is the point where a domestic scale starts guessing at the last digit.
Half, double and triple
Half of 1 cup is 1.45 ounces of ground coffee. Double it and you have 5.78 ounces; triple it and you are at 8.68 ounces. A batch cut to a quarter needs 0.723 ounce.
Multiply or divide the whole line at once rather than converting each step; the answer is the same and there is less to get wrong.
The exact figure and the one worth using
The exact figure for 1 cup is 2.89. Written the way most cooks would write it, 3 ounces, it is out by 0.108 — about 3.7 per cent. On one batch that is invisible.
Scaled four times the gap is 0.43, which is where it starts to show in anything that has to set.
Other ways this gets asked
These are the other phrasings that lead here, and the chart handles them all:
How Many Ounces in a Cup of Ground Coffee?
1 cup is 2.89 ounces.
What is 16 cups of coffee in ounces?
16 cups is 46.3 ounces.
How many ounces are in 2 cups of coffee?
2 cups is 5.78 ounces.
Related conversions
For every kitchen figure in one place, see the full conversion chart.
