Leaveners, Salt & Spices
Convert ounces of baking soda to cups
One ounce of baking soda weighs about 0.129 cup, and half a ounce comes to roughly 0.064 cup. Enter any amount below to convert it, or use the chart further down as a quick reference while you cook.
1 oz of baking soda =
0.129 cup
About 1/8 cup in recipe notation
- ml
- 30.5
- tbsp
- 2.06
Baking Soda: 220 g per US cup · NIST Handbook 133. 1 teaspoon = 4.6 g. Baking soda is roughly 3–4 times stronger than baking powder, so never swap 1:1.
Full baking soda chart →Baking Soda at a glance
Every number on this page comes from a single figure: 220 grams per US cup (NIST Handbook 133).
- 1 cup
- 220 g
- 1 tablespoon
- 13.8 g
- 1 teaspoon
- 4.58 g
- 1 cup in ounces
- 7.76 oz
- 100 g in cups
- 0.455 cups
- Density
- 0.93 g/ml
ounces to cups chart for baking soda
Print it, screenshot it, or bookmark this page — these are the amounts recipes ask for most often.
| Ounces (weight) | Cups (US) | Tablespoons (US) | Millilitres |
|---|---|---|---|
| 0.5 oz | 0.064 cup | 1.03 tbsp | 15.2 ml |
| 1 oz | 0.129 cup | 2.06 tbsp | 30.5 ml |
| 2 oz | 0.258 cup | 4.12 tbsp | 61 ml |
| 3 oz | 0.387 cup | 6.19 tbsp | 91.5 ml |
| 4 oz | 0.515 cup | 8.25 tbsp | 122 ml |
| 5 oz | 0.644 cup | 10.3 tbsp | 152 ml |
| 6 oz | 0.773 cup | 12.4 tbsp | 183 ml |
| 8 oz | 1.03 cup | 16.5 tbsp | 244 ml |
| 12 oz | 1.55 cup | 24.7 tbsp | 366 ml |
| 16 oz | 2.06 cup | 33 tbsp | 488 ml |
How this conversion is calculated
Volume-to-weight conversions are only as good as the density behind them. We treat baking soda as 220 g per US customary cup, which works out to 0.930 g/ml. From there:
- Your ounces figure is converted into millilitres or grams using standard unit sizes (oz = 28.3 g).
- The density above bridges volume and weight in whichever direction you need.
- The result is rounded the way a cook would round it — to the nearest gram, or to a usable fraction such as 1/2 cups.
Measuring baking soda accurately
1 teaspoon = 4.6 g. Baking soda is roughly 3–4 times stronger than baking powder, so never swap 1:1.
If a recipe matters to you — bread, macarons, anything with a tight hydration or ratio — weigh it. A £10 digital scale removes the single largest source of variation in home baking, and it is faster than washing three measuring cups.
When cups are fine
- Liquids measured in a proper jug, where volume is the honest unit anyway.
- Forgiving savoury cooking: soups, stews, stir-fries, marinades.
- Small amounts of leaveners and spices, as long as you use level spoons.
Frequently asked questions
How many cups are in 1 ounce of baking soda?
1 ounce of baking soda is 0.129 cup. This is based on a density of 220 g per US cup.
How many cups are in 2 ounces of baking soda?
2 ounces of baking soda is 0.258 cup, and 0.064 cup for half a ounce.
How much is 100 g of baking soda in cups?
100 g of baking soda is about 1/2 cups. Weight is always the more reliable measurement, so use a scale when the recipe gives grams.
Why do other sites give a different number for baking soda?
1 teaspoon = 4.6 g. Baking soda is roughly 3–4 times stronger than baking powder, so never swap 1:1.
Do UK and Australian cups give the same result?
No. A US customary cup is 236.6 ml, a metric cup used in Australia and New Zealand is 250 ml, and an old UK imperial cup is 284 ml. Our default is the US cup, but you can pick metric cups in the converter.