The classic overnight oats ratio is 1 part oats to 1 part milk by volume, which is about 40 g of old fashioned oats to 113.5 g of milk. That's Quaker's own base recipe: 1/2 cup of oats and 1/2 cup of milk, chilled for at least 8 hours. By weight, it works out to roughly 2.5 to 2.8 g of milk for every 1 g of oats.
| Jars | Old fashioned oats | Milk |
|---|---|---|
| 1 | 40 g (1/2 cup) | 113.5 g (1/2 cup) |
| 2 | 80 g (1 cup) | 227 g (1 cup) |
| 3 | 120 g (1 1/2 cups) | 340.5 g (1 1/2 cups) |
| 4 | 160 g (2 cups) | 454 g (2 cups) |
| 5 | 200 g (2 1/2 cups) | 568 g (2 1/2 cups) |
Why oat weights vary
Not every half cup of oats weighs the same. The Quaker Old Fashioned Oats label lists 1/2 cup at 40 g. The King Arthur Baking ingredient weight chart puts 1 cup of old fashioned or quick oats at 89 g, which is 44.5 g per half cup. King Arthur even lists its own rolled oats at 113 g per cup, much heavier than the 89 g figure.
That spread comes from flake size and thickness, how tightly the oats settle in the cup, and whether you scoop or spoon them in. A 4 or 5 g difference per jar doesn't sound like much, but it's enough to change the texture from one jar to the next. Weighing gives you the same texture every morning, whatever brand you buy.
Adjusting the overnight oats ratio
Think of 40 g of oats to 113.5 g of milk as your starting point, then tweak it to taste:
- Thicker and spoonable: keep the oats at 40 g and pour a little less milk.
- Looser and creamy: add a splash more milk, a few grams at a time.
- Adding yogurt: yogurt brings extra creaminess, so you may want to trim the milk slightly to keep the same consistency.
- Adding chia: chia seeds absorb liquid as they sit, so the jar thickens more. Add a bit of extra milk to balance them.
Write down the exact grams when you hit the texture you love. That's your personal ratio, and it'll work every time.
Here are the common extras by weight, based on the King Arthur Baking chart:
| Add in | Amount | Grams |
|---|---|---|
| Yogurt | 1/4 cup | 56.8 g |
| Chia seeds | 1 tbsp | 9.3 g |
| Maple syrup | 1 tbsp | 19.5 g |
| Honey | 1 tbsp | 21 g |
How to make overnight oats by weight
- Set your jar on the scale and press tare.
- Add the oats to 40 g.
- Tare again and pour in the milk to 113.5 g, or your adjusted amount.
- Add any extras, taring before each one so the numbers stay simple.
- Stir well, making sure no dry oats are stuck at the bottom.
- Chill. Quaker recommends at least 8 hours in a refrigerator at 40°F or colder.
- Top in the morning with fruit. Quaker's base suggests 1/2 cup of chopped strawberries, blueberries or apples.
Common mistakes
- Using a different oat without adjusting. These numbers are for old fashioned rolled oats. Other cuts absorb liquid differently, so test a jar before making a week's worth.
- Measuring sticky sweeteners with a spoon. Honey and maple syrup cling to the spoon, so you never get it all out. Weighing straight into the jar solves that.
- Skipping the stir. Oats packed at the bottom can stay dry if the milk never reaches them.
- Not chilling long enough. Give them the full 8 hours so the oats soften all the way through.
For the small add ins, a MeasureMate digital measuring spoon makes things simple. It scoops and weighs in one step, so you can scoop chia seeds and read 9.3 g right on the display. It reads in 0.1 g steps, the tare button zeroes the reading between ingredients, and the spoon head comes off for washing after honey or syrup.
Quick questions
What is the ratio of oats to milk for overnight oats?
Quaker's base is 1/2 cup of old fashioned oats to 1/2 cup of milk, a 1 to 1 ratio by volume. By weight, that's about 40 g of oats to 113.5 g of milk.
How long do overnight oats need to soak?
At least 8 hours in the refrigerator, according to Quaker. Making them before bed is the easy way to hit that.
Weights based on the Quaker Old Fashioned Oats label and overnight oats recipe, and the King Arthur Baking ingredient weight chart.