Herbs & Spices
Onion Powder Conversion
Onion Powder weighs 115g per US cup.
Conventionally measured by the teaspoon.
| Amount | Grams | Ounces |
|---|---|---|
| 1 cup | 115.0 g | 4.06 oz |
| 1/2 cup | 57.5 g | 2.03 oz |
| 1/4 cup | 28.8 g | 1.01 oz |
| 1 tbsp | 7.2 g | 0.25 oz |
| 1 tsp | 2.4 g | 0.08 oz |
| 100 g | 100.0 g | 3.53 oz |
Need a different amount? Use the full Ingredient Converter tool.
Onion powder's 115g-per-cup figure follows the same mathematical-extrapolation pattern as garlic powder — it's used by the teaspoon, made through a similar dehydration-and-grinding process applied to onions instead of garlic, producing a concentrated, shelf-stable seasoning rather than a true substitute for fresh onion's texture and moisture.
That processing shift, like garlic powder's, mellows and sweetens onion's flavor somewhat compared to raw onion's sharper, more pungent bite — onion powder delivers real onion flavor without any of raw onion's texture or moisture, which is exactly why this site's substitute guidance for chopped onion specifically flags it as suited to sauces and soups rather than any dish where visible, textured onion is the point.
Onion powder and onion salt are genuinely different products worth distinguishing carefully — onion salt is onion powder blended with salt at a fixed ratio, meaning a recipe using onion salt in place of onion powder needs its other added salt reduced accordingly, or the dish risks turning out significantly over-salted.
Onion powder is dehydrated, ground onion, and its 100g-per-cup figure exists mainly for completeness — almost no recipe genuinely calls for a full cup of it, since a teaspoon or two typically delivers the intensity of far more fresh onion by volume, concentrated by the dehydration process into a fraction of fresh onion's original bulk.
Unlike fresh onion, onion powder disperses evenly through a dry rub or marinade without the textural bite raw or sautéed onion pieces would add, which is exactly why it's favored in spice blends and dry rubs where a smooth, uniform seasoning matters more than visible onion pieces.
It keeps far longer in the pantry than fresh onion, with little of the sharp odor raw onion carries.
It's worth checking the label for added anti-caking agents, which some brands include and others don't.
Frequently asked questions
Is onion powder the same as onion salt?
No — onion salt is simply onion powder mixed with a set amount of table salt, so reaching for it in place of plain onion powder without cutting back elsewhere in the recipe can quietly push the finished dish's sodium well past what was intended.
Can onion powder replace fresh chopped onion in a recipe?
It brings genuine onion flavor to a dish but none of the bite, moisture, or visible texture a fresh chopped onion adds — this site steers it toward sauces, soups, and dry seasoning blends, and away from anything where you actually want to see and bite into onion pieces.
Why does onion powder taste sweeter and less sharp than raw onion?
The dehydration and grinding process mellows onion's naturally sharp, pungent raw bite, similar to what happens with garlic powder, producing a milder, somewhat sweeter concentrated flavor than fresh onion delivers.
Does onion powder go bad over time?
Sealed and kept dry, it stays safe to use well past any date on the jar — what actually changes is strength, since like other ground spices it gradually loses flavor potency, leaving an older jar tasting noticeably weaker in onion flavor than a fresh one.
How much onion powder replaces one medium chopped onion in a recipe?
Roughly 1 tablespoon of onion powder per 1 medium chopped onion (about 1 cup), a useful working ratio for converting a recipe written around fresh onion into one using the dried, powdered form instead.