Molasses — Measurement Converter
1 cup of molasses (also called treacle) weighs about 337 g, which makes a tablespoon 21.1 g and a teaspoon 7.02 g. Small amounts are easier to measure with spoons than to weigh.
💡 Tip: Oil the cup so molasses releases cleanly. Blackstrap is much more bitter and concentrated — don't swap it 1:1 for regular molasses.
Molasses by weight: grams to cups
| Grams | Amount | Ounces |
|---|---|---|
| 15 | 2 1/8 tsp | 0.53 |
| 20 | 2 7/8 tsp | 0.71 |
| 30 | 1 3/8 tbsp | 1.06 |
| 50 | 2 3/8 tbsp | 1.76 |
| 100 | 1/3 cup | 3.53 |
| 150 | 1/2 cup | 5.29 |
| 200 | 5/8 cup | 7.05 |
| 250 | 3/4 cup | 8.82 |
| 300 | 7/8 cup | 10.6 |
| 340 | 1 cup | 12 |
| 450 | 1 1/3 cups | 15.9 |
Molasses, treacle and the blackstrap warning
Molasses is thick and heavy — a cup weighs about 337 g (11.9 oz), with each tablespoon around 21 g. Oil the cup or spoon first so it releases cleanly. In the UK, dark treacle is the closest equivalent, while golden syrup is much milder and not a true swap. There are grades: mild (light), full/dark, and blackstrap, which is the most concentrated and bitter — don't substitute it 1:1 for regular molasses or your gingerbread will turn harsh. Molasses adds moisture and acidity, which is why recipes using it often pair it with baking soda.
Molasses cup measurements, in grams
| Cups | Grams | Ounces |
|---|---|---|
| 1/8 | 42.1 | 1.49 |
| 1/4 | 84.3 | 2.97 |
| 1/3 | 112 | 3.96 |
| 1/2 | 169 | 5.94 |
| 2/3 | 225 | 7.92 |
| 3/4 | 253 | 8.92 |
| 1 | 337 | 11.9 |
| 1 1/2 | 506 | 17.8 |
Spoon reference: 1 tablespoon ≈ 21.1 g, 1 teaspoon ≈ 7.02 g.
How molasses compares with other syrups & spreads
337 g per cup places molasses in the middle of its category — lighter than honey (340 g) and heavier than agave syrup (330 g).
That gap matters when you substitute by volume: use a cup of honey where the recipe wanted molasses and you have added about 3 g extra — 1% more than intended. Weighing instead of scooping removes the problem.
Frequently asked questions
- How many grams is a tablespoon of molasses?
- About 21.1 g per tablespoon — there are 16 tablespoons in a cup.
- How many grams is 2 cups of molasses?
- About 674 g, based on roughly 337 g per cup.
- How many cups is 150g of molasses?
- About ½ cup.
- Is molasses the same as treacle?
- Closely — UK dark or black treacle is the nearest equivalent to molasses. Golden syrup is far milder and isn't a direct substitute.
- Can I use blackstrap molasses instead of regular molasses?
- Not 1:1 — blackstrap is much more concentrated and bitter, so use less or it will overpower the recipe.
- What can I substitute for molasses?
- Dark treacle, or a mix of brown sugar with a little water; honey or maple syrup work for sweetness but lack the deep flavour.
- How many grams is 1 cup of molasses?
- A level US cup of molasses comes to roughly 337 g (11.9 oz on a scale).
- How many ounces is 1 cup of molasses?
- About 11.9 oz. Note that is weight, not fluid ounces — a cup is always 8 fl oz whatever is in it.
- Why do my numbers differ slightly?
- Viscosity depends on temperature. Warm syrup flows into the corners of a cup and cold syrup leaves gaps behind, and a sticky film always stays in the cup — which is why weighing straight into the bowl is easier.