One cup of potato starch is 160 grams, so converting cups of potato starch to grams means multiplying by 160. That factor is specific to this ingredient — it comes from its density, not from any relationship between the two units.
The density behind that figure is 0.67628 g per mL, against 1.00 for water. A cup of water weighs 236.6 g and a cup of potato starch weighs 160 g, so this ingredient is 67.63% as heavy as the same volume of water — the single fact the whole page rests on.
A cup of potato starch is 160 g when it is measured the standard way, but how it gets into the cup changes the answer: between about 144 g and 192 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.
Grams are the unit this conversion is really for. A domestic scale resolves to a gram, which is 0.625% of a cup of potato starch, so weighing gets an accuracy no measuring cup can reach. A 500 g pack of it is 3.125 cups, and a 1 kg pack 6.25.
The condition this weight assumes: Denser than cornstarch, and not the same product as potato flour despite the similar name.
The formula
cups- The amount of potato starch you are converting, in cups
160- Grams per cup for potato starch, from its density of 0.67628 g/mL
grams- The equivalent quantity in grams
How it works, step by step
- Enter the quantity in cups.
- It is multiplied by 160, the grams-per-cup figure for potato starch.
- The result appears in grams, with a second reading in oz beneath it.
- Use the measure table if you want a standard recipe quantity rather than a number you type in.
Worked examples
1/3 cup of potato starch in grams
Take 1/3 cup of potato starch: 0.333333 × 160 gives 53.3333 grams. Doubling the batch takes it to 106.667 grams, because the relationship is a straight proportion once the density is known.
3/4 cup of potato starch in grams
A recipe calling for 3/4 cup of potato starch needs 120 grams on the scale. The arithmetic is 0.75 × 160 = 120, and halving the recipe halves the weight to 60 grams.
3 cup of potato starch in grams
A recipe calling for 3 cup of potato starch needs 480 grams on the scale. The arithmetic is 3 × 160 = 480, and halving the recipe halves the weight to 240 grams.
How to read your score
Frequently asked questions
How many grams are in 1 cup of potato starch?
One cup of potato starch is 160 grams. Half that quantity is 80 grams and double it is 320 grams, so the figure scales straight up and down — there is no offset in this conversion, only the factor.
Why is a cup of potato starch not 236 g like water?
Because weight per cup depends on what is in the cup. Potato starch has a density of 0.67628 g per mL where water has 1.00, so a cup of it weighs 160 g rather than 236.6 g. That is a difference of 76.6 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 potato starch by roughly 20% — about 16 g either side of 160 g — because denser than cornstarch, and not the same product as potato flour despite the similar name. Weighing removes the question entirely.
Is a fluid ounce of potato starch 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 potato starch weighs 0.7055 oz, so the two readings differ by 29.5%. 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 potato starch would weigh 169.07 g instead of 160 g — 9.07 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 potato starch — roughly 32 g on a 160 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 many cups of potato starch is 500 g?
500 g of potato starch is 3.125 cups — 0.00625 cups to one gram, so 500 × 0.00625 = 3.125. Going that way is a division by 160, or a multiplication by 0.00625 if you prefer.
Potato starch in cups and grams
| Cups | Grams | Unrounded |
|---|---|---|
| 1/8 cup | 20 g | 20 |
| 1/4 cup | 40 g | 40 |
| 1/3 cup | 53.3333 g | 53.33333333 |
| 1/2 cup | 80 g | 80 |
| 2/3 cup | 106.667 g | 106.6666667 |
| 3/4 cup | 120 g | 120 |
| 1 cup | 160 g | 160 |
| 1 1/2 cup | 240 g | 240 |
| 2 cup | 320 g | 320 |
| 3 cup | 480 g | 480 |
| 4 cup | 640 g | 640 |
Based on 160 g per cup of potato starch. One cup of potato starch is 160 grams.
| Measure | Grams | Ounces | Millilitres |
|---|---|---|---|
| 1 cup | 160 g | 5.64 oz | 236.6 mL |
| 3/4 cup | 120 g | 4.23 oz | 177.4 mL |
| 2/3 cup | 106.7 g | 3.76 oz | 157.7 mL |
| 1/2 cup | 80 g | 2.82 oz | 118.3 mL |
| 1/3 cup | 53.33 g | 1.88 oz | 78.86 mL |
| 1/4 cup | 40 g | 1.41 oz | 59.15 mL |
| 1 tbsp | 10 g | 0.353 oz | 14.79 mL |
| 1 tsp | 3.333 g | 0.118 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) |
|---|---|---|---|
| Cornmeal | 138 g | 4.868 oz | 0.5833 |
| Graham cracker crumbs | 142 g | 5.009 oz | 0.6002 |
| Rice flour | 158 g | 5.573 oz | 0.6678 |
| Potato starch (this page) | 160 g | 5.644 oz | 0.6763 |
| Steel-cut oats | 160 g | 5.644 oz | 0.6763 |
| Semolina | 167 g | 5.891 oz | 0.7059 |
| Uncooked quinoa | 170 g | 5.997 oz | 0.7185 |
Ordered by weight. The spread across this group is why a single generic cups-to-grams factor cannot work.