One teaspoon of rolled oats is 1.875 grams, so converting teaspoons of rolled oats to grams means multiplying by 1.875. 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 0.38041 g per mL, against 1.00 for water. A cup of water weighs 236.6 g and a cup of rolled oats weighs 90 g, so this ingredient is 38.04% as heavy as the same volume of water — the single fact the whole page rests on.
A level teaspoon of rolled oats weighs 1.875 g. A kitchen scale that reads to the nearest gram is therefore working at roughly 53.3% resolution on a single spoonful, which is why measuring spoons beat scales below about 5 g and lose to them above it. Three teaspoons make a tablespoon, so the same spoonful is 5.625 g if the recipe scales up.
Grams are the unit this conversion is really for. A domestic scale resolves to a gram, which is 1.11% of a cup of rolled oats, so weighing gets an accuracy no measuring cup can reach. A 500 g pack of it is 5.556 cups, and a 1 kg pack 11.11.
The condition this weight assumes: Old-fashioned flakes. Very light for their volume because of the air trapped between them.
The formula
teaspoons- The amount of rolled oats you are converting, in teaspoons
1.875- Grams per teaspoon for rolled oats, from its density of 0.38041 g/mL
grams- The equivalent quantity in grams
How it works, step by step
- Enter the quantity in teaspoons.
- It is multiplied by 1.875, the grams-per-teaspoon figure for rolled oats.
- 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
3/4 tsp of rolled oats in grams
A recipe calling for 3/4 tsp of rolled oats needs 1.40625 grams on the scale. The arithmetic is 0.75 × 1.875 = 1.40625, and halving the recipe halves the weight to 0.703125 grams.
1 1/2 tsp of rolled oats in grams
Take 1 1/2 tsp of rolled oats: 1.5 × 1.875 gives 2.8125 grams. Doubling the batch takes it to 5.625 grams, because the relationship is a straight proportion once the density is known.
4 tsp of rolled oats in grams
A recipe calling for 4 tsp of rolled oats needs 7.5 grams on the scale. The arithmetic is 4 × 1.875 = 7.5, and halving the recipe halves the weight to 3.75 grams.
How to read your score
Frequently asked questions
How many grams are in 1 tsp of rolled oats?
One teaspoon of rolled oats is 1.875 grams. Half that quantity is 0.9375 grams and double it is 3.75 grams, so the figure scales straight up and down — there is no offset in this conversion, only the factor.
Why is a cup of rolled oats not 236 g like water?
Because weight per cup depends on what is in the cup. Rolled oats has a density of 0.38041 g per mL where water has 1.00, so a cup of it weighs 90 g rather than 236.6 g. That is a difference of 146.6 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 rolled oats by roughly 20% — about 9 g either side of 90 g — because old-fashioned flakes. Weighing removes the question entirely.
Is a fluid ounce of rolled oats 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 rolled oats weighs 0.3968 oz, so the two readings differ by 60.3%. 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 rolled oats would weigh 95.102 g instead of 90 g — 5.1 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?
At this size the spoon wins. One teaspoon of rolled oats is 1.875 g, and a scale reading to the nearest gram is working at 53.3% resolution on that — a measuring spoon is the more accurate instrument below about 5 g, which is why spice quantities are still written in spoons.
How many teaspoons of rolled oats is 500 g?
500 g of rolled oats is 266.67 teaspoons — 0.533333 teaspoons to one gram, so 500 × 0.533333 = 266.67. Going that way is a division by 1.875, or a multiplication by 0.533333 if you prefer.
Rolled oats in teaspoons and grams
| Teaspoons | Grams | Unrounded |
|---|---|---|
| 1/4 tsp | 0.46875 g | 0.46875 |
| 1/2 tsp | 0.9375 g | 0.9375 |
| 3/4 tsp | 1.40625 g | 1.40625 |
| 1 tsp | 1.875 g | 1.875 |
| 1 1/2 tsp | 2.8125 g | 2.8125 |
| 2 tsp | 3.75 g | 3.75 |
| 3 tsp | 5.625 g | 5.625 |
| 4 tsp | 7.5 g | 7.5 |
| 6 tsp | 11.25 g | 11.25 |
Based on 90 g per cup of rolled oats. One teaspoon of rolled oats is 1.875 grams.
| Measure | Grams | Ounces | Millilitres |
|---|---|---|---|
| 1 cup | 90 g | 3.17 oz | 236.6 mL |
| 1 tbsp | 5.625 g | 0.198 oz | 14.79 mL |
| 2 tsp | 3.75 g | 0.132 oz | 9.858 mL |
| 1 tsp | 1.875 g | 0.0661 oz | 4.929 mL |
| 3/4 tsp | 1.406 g | 0.0496 oz | 3.697 mL |
| 1/2 tsp | 0.9375 g | 0.0331 oz | 2.464 mL |
| 1/4 tsp | 0.4688 g | 0.0165 oz | 1.232 mL |
| 1/8 tsp | 0.2344 g | 0.00827 oz | 0.6161 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 (this page) | 90 g | 3.175 oz | 0.3804 |
| Oat flour | 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.