To convert ounces of oat flour into cups, multiply by 0.30814699: one ounce comes to 0.30814699 cups. Every ingredient has its own figure here, because the units are measuring different things and only the density links them.
Water is the yardstick: 1 mL of it weighs 1 g. Oat flour comes in at 0.38886 g per mL, or 38.89% of water, which is why a cup of it is 92 g rather than 236.6 g. Volume and weight only line up for water, and only in metric.
A cup of oat flour is 92 g when it is measured the standard way, but how it gets into the cup changes the answer: between about 82.8 g and 110.4 g covers the range from lightly spooned to firmly packed. That 20% spread is larger than most of the adjustments recipes fuss over, and it disappears entirely the moment the ingredient is weighed instead.
One cup of oat flour is 3.245 oz. US kitchen scales usually step in eighths of an ounce, which is 3.54 g — around 3.85% of a cup of this ingredient, so the scale is precise enough for a full cup and coarse for a spoonful. That is why recipes mix the two systems: ounces for the bulk, spoons for the small amounts.
How the figure is arrived at: Ground rolled oats, and almost as light per cup as the flakes it came from.
The formula
ounces- The amount of oat flour you are converting, in ounces
0.308146990489- Cups per ounce for oat flour, from its density of 0.38886 g/mL
cups- The equivalent quantity in cups
How it works, step by step
- Enter the quantity in ounces.
- It is multiplied by 0.308146990489, the cups-per-ounce figure for oat flour.
- The result appears in cups, with a second reading in tbsp beneath it.
- Use the measure table if you want a standard recipe quantity rather than a number you type in.
Worked examples
2 oz of oat flour in cups
2 oz of oat flour weighs out at 0.616294 cups. Divide 0.616294 by 0.30814699 and you get back to 2 oz, which is the quickest check that the factor is the right way up.
4 oz of oat flour in cups
4 oz of oat flour weighs out at 1.23259 cups. Divide 1.23259 by 0.30814699 and you get back to 4 oz, which is the quickest check that the factor is the right way up.
12 oz of oat flour in cups
Take 12 oz of oat flour: 12 × 0.30814699 gives 3.69776 cups. Doubling the batch takes it to 7.39553 cups, because the relationship is a straight proportion once the density is known.
How to read your score
Frequently asked questions
How many cups are in 1 oz of oat flour?
One ounce of oat flour is 0.30814699 cups. Half that quantity is 0.154073 cups and double it is 0.616294 cups, so the figure scales straight up and down — there is no offset in this conversion, only the factor.
Why is a cup of oat flour not 236 g like water?
Because weight per cup depends on what is in the cup. Oat flour has a density of 0.38886 g per mL where water has 1.00, so a cup of it weighs 92 g rather than 236.6 g. That is a difference of 144.6 g per cup, and it is the reason a single volume-to-weight factor cannot be applied to every ingredient.
Does how I measure it change the weight?
Yes, and by more than most people expect. Handling changes the weight of a cup of oat flour by roughly 20% — about 9.2 g either side of 92 g — because ground rolled oats, and almost as light per cup as the flakes it came from. Weighing removes the question entirely.
Is a fluid ounce of oat flour the same as an ounce?
No. A fluid ounce is a volume — one eighth of a US cup, 29.57 mL — and an ounce is a weight. One fluid ounce of oat flour weighs 0.4057 oz, so the two readings differ by 59.4%. They coincide only for something with the density of water, and then only roughly.
Is this a US cup or a metric cup?
US customary: 236.59 mL, which is the cup every US recipe means. A metric cup is 250 mL, so the same cup of oat flour would weigh 97.215 g instead of 92 g — 5.22 g more, or 5.67%. Australian and some European recipes use the metric cup, and the difference is large enough to matter in baking.
Do I need a scale for this, or will measuring cups do?
A scale, if the result matters. Volume measuring carries a spread of about 20% for oat flour — roughly 18.4 g on a 92 g cup — while a domestic scale is accurate to a gram or two. For anything where the ratio of ingredients drives the outcome, bread and pastry above all, weigh it.
How much does 2 cup of oat flour weigh?
2 cup of oat flour comes to 184 g, or 6.4904 ounces. This page runs that calculation in reverse — enter a weight and it returns the volume — and the cups-to-ounces page does it in the direction the question is usually asked.
Oat flour in ounces and cups
| Ounces | Cups | Unrounded |
|---|---|---|
| 1/2 oz | 0.154073 cup | 0.1540734952 |
| 1 oz | 0.308147 cup | 0.3081469905 |
| 2 oz | 0.616294 cup | 0.616293981 |
| 3 oz | 0.924441 cup | 0.9244409715 |
| 4 oz | 1.23259 cup | 1.232587962 |
| 6 oz | 1.84888 cup | 1.848881943 |
| 8 oz | 2.46518 cup | 2.465175924 |
| 12 oz | 3.69776 cup | 3.697763886 |
| 16 oz | 4.93035 cup | 4.930351848 |
Based on 92 g per cup of oat flour. One ounce of oat flour is 0.30814699 cups.
| Measure | Grams | Ounces | Millilitres |
|---|---|---|---|
| 1 cup | 92 g | 3.25 oz | 236.6 mL |
| 3/4 cup | 69 g | 2.43 oz | 177.4 mL |
| 2/3 cup | 61.33 g | 2.16 oz | 157.7 mL |
| 1/2 cup | 46 g | 1.62 oz | 118.3 mL |
| 1/3 cup | 30.67 g | 1.08 oz | 78.86 mL |
| 1/4 cup | 23 g | 0.811 oz | 59.15 mL |
| 1 tbsp | 5.75 g | 0.203 oz | 14.79 mL |
| 1 tsp | 1.917 g | 0.0676 oz | 4.929 mL |
US customary measures: 1 cup = 236.59 mL, 1 tbsp = 14.79 mL, 1 tsp = 4.93 mL.
| Ingredient | Grams per cup | Ounces per cup | Density (g/mL) |
|---|---|---|---|
| Panko breadcrumbs | 60 g | 2.116 oz | 0.2536 |
| Cocoa powder | 85 g | 2.998 oz | 0.3593 |
| Rolled oats | 90 g | 3.175 oz | 0.3804 |
| Oat flour (this page) | 92 g | 3.245 oz | 0.3889 |
| Almond flour | 96 g | 3.386 oz | 0.4058 |
| Rye flour | 102 g | 3.598 oz | 0.4311 |
| Dry breadcrumbs | 108 g | 3.81 oz | 0.4565 |
Ordered by weight. The spread across this group is why a single generic cups-to-grams factor cannot work.