Ounces to Cups Converter

What this does

So a recipe gives you an ingredient by weight in ounces, but you would rather measure it out in cups. This converter goes that way round. Enter the ounces, pick the ingredient and your cup size, and it tells you how many cups that is. The ingredient matters, because the same weight fills a different number of cups depending on how heavy it is.

How to use it

1. Enter the amount in ounces.
2. Pick your cup size, US Legal (240 ml) or Imperial (284 ml).
3. Choose the ingredient, then press Calculate.

The ounces here are a weight, the kind your scale shows, not fluid ounces.

Why the ingredient matters

Weight and volume are two different things, and the bridge between them is the ingredient's density. A heavy ingredient packs a lot of weight into a small space, so it fills fewer cups, while a light one spreads out and fills more.

Picture 8 ounces of each. Eight ounces of water is just under a cup, because water is dense. Eight ounces of flour is well over a cup, because flour is light and fluffy. Same weight, different number of cups, which is exactly why the tool asks you to choose the ingredient first. Flour, as ever, is the least consistent, so treat its result as a close guide.

How the conversion works

The tool divides your weight by how much one cup of that ingredient weighs. In plain form:

cups = ounces ÷ ounces per cup of the ingredient

For water, a US Legal cup weighs about 8.47 ounces, so 8.47 ounces of water is right about one cup. A lighter ingredient weighs less per cup, so the same ounces give you more cups.

Questions people ask

References

1. King Arthur Baking. Ingredient Weight Chart. https://www.kingarthurbaking.com/learn/ingredient-weight-chart
2. National Institute of Standards and Technology. Handbook 44, Appendix C: General Tables of Units of Measurement. https://www.nist.gov/document/nist-hb-44-2024-appendix-c-general-tables-units-measurement