Water Grams to Cups Converter
Convert water from grams to cups using ingredient-specific baking measurements.
100 grams of water ≈
0.42US cups
About ⅜ cup + 1 tablespoon
Based on 1 US cup of water = 240g
Data last verified: August 5, 2026
Convert grams to cups
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100 grams of Water =
0.42US cups
Approximately ⅜ cup + 1 tablespoon
Based on 1 US cup of Water = 240g
1 US cup of Water = 240g
Measured poured to the 240 ml line and read at eye level (fresh water, near room temperature, based on the US cup / 240 ml)
Water grams to cups conversion table
| Grams | Cups |
|---|---|
| 25g | 0.10 cups |
| 50g | 0.21 cups |
| 75g | 0.31 cups |
| 100g | 0.42 cups |
| 120g | 0.50 cups |
| 125g | 0.52 cups |
| 150g | 0.63 cups |
| 200g | 0.83 cups |
| 225g | 0.94 cups |
| 240g | 1.00 cups |
| 250g | 1.04 cups |
| 300g | 1.25 cups |
| 400g | 1.67 cups |
| 500g | 2.08 cups |
Kitchen fraction approximation
Sources & how they compare
| Source | Reported value | Comparable source-cup value | Type | Measurement method | Adopted here | Checked |
|---|---|---|---|---|---|---|
| U.S. Geological Survey — Water Density | 1 g/1 ml (approximate) | 240g | Direct | fresh-water density; temperature dependent | Adopted | 2026-08-05 |
| King Arthur Baking — Ingredient Weight Chart | 227 g/1 source cup (exact volume unknown) | 227g | Direct | poured liquid | 2026-08-05 |
A comparable source-cup value only scales a half-cup or tablespoon serving to one source cup. When a source does not state the cup's exact volume, we do not present it as a fixed-milliliter normalization.
Measurement notes
- At ordinary kitchen temperatures, fresh water is close to 1 gram per milliliter, so 240 ml is about 240g.
- Temperature and dissolved minerals change density slightly; this difference is usually immaterial in home baking.
- Use a liquid measuring cup on a level surface and read the bottom of the meniscus at eye level.
Common mistakes
- Not measuring water the recommended way — poured to the 240 ml line and read at eye level — is one of the most common sources of error.
- 1 cup of water happens to weigh about the same as water (240g) — most baking ingredients don't.
- Using a dry measuring cup instead of a liquid measuring cup.
Related amount conversions
Frequently asked questions
How many cups is 100 grams of water?
100 grams of water is about 0.42 cups, based on 1 US cup (240 ml) = 240g.
How many grams are in 1 cup of water?
1 US cup of water is about 240 grams, measured poured to the 240 ml line and read at eye level.
Does 1 cup of water weigh the same in a metric cup?
No. A metric cup (250 ml) holds slightly more than a US cup (240 ml), so 1 metric cup of water is about 250g, compared with 240g in a US cup.
What's the best way to measure water accurately?
For the most accurate result, poured to the 240 ml line and read at eye level, and use a kitchen scale when your recipe calls for a precise weight.
Can I convert cups of water back to grams?
Yes, use the Cups to Grams tool with water selected to convert any cup amount back into grams.
Why does water convert differently from other ingredients?
Grams measure weight and cups measure volume, so the conversion depends on how dense water is. A cup of water weighs 240g, while a denser or lighter ingredient weighs a different amount per cup.
Where do these numbers come from?
See how we measure ingredient density and verify each grams-per-cup value.