Grams to Fl Oz Converter
Convert grams to fluid ounces — or back again — for water, milk, flour, sugar, honey, oil and more. Since weight and volume aren't the same thing, this converter uses the correct density for your ingredient automatically.
✓ 16 built-in ingredient densities ✓ US and UK fluid ounces ✓ Works on mobile
Grams ⇄ Fluid Ounces Converter
Why Grams and Fluid Ounces Don't Convert Directly
One measures weight, the other measures volume — density is the missing link.
The gram is a unit of mass, the same kind of measurement as kilograms or pounds. The fluid ounce is a unit of volume, the same kind of measurement as liters, cubic centimeters, or gallons. Because these are two fundamentally different physical quantities, there's no single, universal conversion factor between grams and fluid ounces the way there is between, say, grams and kilograms.
The missing piece is density — how much mass is packed into a given volume of a specific substance. A gram of water takes up a very different amount of space than a gram of flour, honey, or oil, because each substance packs its mass differently. This is exactly why baking recipes that mix weight and volume measurements need to specify which ingredient is being measured, not just the number.
This calculator includes built-in density values for common cooking and baking ingredients — water, milk, flour, sugar, honey, oil and more — so you can convert accurately without looking up a density figure yourself, or enter a custom density for anything not on the list.
Grams to Fl Oz Formula
The two-step calculation this converter performs.
The first step: divide the mass in grams by the substance's density in grams per cubic centimeter to get the volume in cubic centimeters.
The second step: divide the volume in cubic centimeters by 29.574 to convert to US fluid ounces.
For UK (imperial) fluid ounces instead, divide the volume in cubic centimeters by 28.413 — a slightly smaller unit than the US fluid ounce.
Working backward: multiply fluid ounces by 29.574 (US) or 28.413 (UK) to get cm³, then multiply by density to get mass in grams.
How the Grams to Fl Oz Converter Works
Three steps to an accurate, density-aware conversion.
Choose Your Substance
Select from 16 built-in ingredients, or choose "Other" to enter a custom density in any of five common units.
Enter Your Value
Type in a weight in grams (or a volume in fluid ounces, if converting the other direction), and choose US or UK fluid ounces.
Automatic Calculation
The calculator divides by density to find volume in cm³, then converts to your chosen fluid ounce standard instantly.
Copy or Share
Copy your converted measurement straight to your clipboard, ready to use in a recipe.
Complete Guide to Converting Grams and Fluid Ounces
What density really means for cooking, and how US and UK fl oz differ.
Why Water Is Close to a 1:1 Conversion
Water has a density very close to 1 gram per cubic centimeter, and since 1 US fluid ounce of water is close to 29.574 grams, water is often used as a mental reference point. Any substance denser than water — like honey or evaporated milk — weighs more than the same volume of water; anything less dense — like flour or oats — weighs less than the same volume of water.
US Fluid Ounces vs UK (Imperial) Fluid Ounces
A US fluid ounce is defined as exactly 29.5735 cm³, while a UK (imperial) fluid ounce is defined as exactly 28.4131 cm³ — meaning the US fluid ounce is slightly larger. This difference is small per ounce but adds up over larger volumes, so it's worth confirming which standard a recipe or product label is using, especially when working between American and British sources.
Why Recipes Mix Weight and Volume at All
Many recipes, especially in North America, measure dry and liquid ingredients by volume (cups, fluid ounces) for convenience, while more precision-focused baking traditions — and much of the rest of the world — measure by weight (grams) instead. Weight measurements are generally more consistent, since a "cup" of flour can pack down differently depending on how it's scooped, while a gram of flour is always the same amount of flour regardless of how it's measured.
Grams to Fl Oz for Common Ingredients
Different ingredients convert very differently between grams and fluid ounces because their densities vary so much: an ounce of water and an ounce of wheat flour occupy the same volume, but the flour weighs noticeably less due to the air trapped between its particles. This is exactly why a single "grams to fl oz" conversion factor can't apply across ingredients, and why this calculator asks which substance you're converting.
Converting Density Between Units
If your density figure comes in a unit other than g/cm³, converting it first is straightforward: multiply kg/m³ by 0.001, lb/ft³ by 0.01601846, lb/in³ by 27.6799, or lb/US gal by 0.1198264, to arrive at the equivalent density in g/cm³. Conveniently, density in g/mL is numerically identical to g/cm³, since a milliliter and a cubic centimeter are the same volume.
When Precision Really Matters
For most everyday cooking, a small rounding difference in density won't noticeably affect a recipe's outcome. For baking — especially bread, pastry, and other recipes sensitive to precise ratios — converting ingredients by weight rather than volume, using an accurate density figure, produces more consistent, repeatable results than eyeballing a volume measurement.
Step-by-Step Grams to Fl Oz Examples
Eight worked conversions across common ingredients.
Example 1 — Water
Convert 100 grams of water to US fluid ounces.
Example 2 — Fresh Milk
Convert 12 fl oz of fresh milk to grams.
Example 3 — Evaporated Milk
Convert 12 fl oz of evaporated milk to grams.
Example 4 — Wheat Flour
Convert 100 grams of wheat flour to US fluid ounces.
Example 5 — Sugar
Convert 1 US fl oz of sugar to grams.
Example 6 — Honey
Convert 50 grams of honey to US fluid ounces.
Example 7 — Converting to UK Fluid Ounces
Convert 100 grams of water to UK fluid ounces.
Example 8 — Custom Density Example
Convert 200 grams of a custom liquid with density 0.95 g/cm³ to US fluid ounces.
Grams to Fl Oz Reference Tables
Common ingredient densities and how they compare per fluid ounce.
| Ingredient | Grams per fl oz |
|---|---|
| Water | 29.574 g |
| Fresh Milk | 30.46 g |
| Evaporated Milk | 31.35 g |
| Sugar | 25.00 g |
| Wheat Flour | 17.744 g |
| Honey | 42.0 g |
| Oil | 27.2 g |
| Standard | Volume in cm³ |
|---|---|
| 1 US fl oz | 29.5735 cm³ |
| 1 UK (imperial) fl oz | 28.4131 cm³ |
| Unit | Equivalent in g/cm³ |
|---|---|
| 1 kg/m³ | 0.001 |
| 1 lb/ft³ | 0.01601846 |
| 1 lb/in³ | 27.6799 |
| 1 lb/US gal | 0.1198264 |
Benefits of Using This Converter
Why a dedicated tool beats a generic weight-to-volume assumption.
Instant, Accurate Results
Get a precise fluid-ounce or gram figure using the correct density for your specific ingredient.
16 Built-In Ingredients
From water and milk to flour, honey, and Nutella, common cooking densities are already built in.
Custom Density Support
Enter your own density in any of five common units if your ingredient isn't in the list.
Works Both Directions
Convert grams to fluid ounces, or fluid ounces back to grams, from the same interface.
US and UK Standards
Choose between US and UK (imperial) fluid ounces, which differ by about 4%.
Mobile-Friendly
Use it right in the kitchen while following a recipe, on any phone or tablet.
Practical Applications of Grams to Fl Oz Conversion
Where this conversion actually comes up in the kitchen and beyond.
Cooking & Baking
Converting between a recipe's weight and volume measurements, especially when following recipes from a different country.
Nutrition & Food Labeling
Comparing nutrition information listed by weight (grams) against serving sizes listed by volume (fl oz).
Recipe Scaling
Scaling a recipe up or down while converting between the units each ingredient happens to be listed in.
Homebrewing & Beverage Making
Converting ingredient weights to fluid volumes for brewing, mixology, and beverage formulation.
International Recipe Conversion
Converting metric-weight recipes from international cookbooks into US or UK volume measurements.
Science & Chemistry Education
Density-based conversion between mass and volume is a foundational concept in early chemistry coursework.
Common Grams to Fl Oz Mistakes
Avoid these errors when converting weight to volume in the kitchen.
Assuming every ingredient converts like water
Only water (and similar liquids) is close to a simple 1:1 gram-to-fl-oz relationship — flour, sugar, honey and oil all convert very differently.
Mixing up US and UK fluid ounces
A US fl oz (29.5735 cm³) is about 4% larger than a UK fl oz (28.4131 cm³) — always confirm which standard a recipe or label is using.
Using the wrong density unit
Mixing up g/cm³ with kg/m³, or forgetting to convert lb/ft³ first, changes the result by orders of magnitude.
Ignoring packing density for dry ingredients
How tightly flour, sugar, or cacao is packed can shift its effective density — spooned-and-leveled flour differs from scooped-and-packed flour.
Confusing mass and weight
Grams measure mass, which is constant, while "weight" technically depends on gravity — for kitchen purposes the distinction rarely matters, but it's worth knowing.
Forgetting that fl oz is a volume unit, not a weight unit
Despite the word "ounce," a fluid ounce measures volume, not weight — treating it as equivalent to a weight ounce (28.35 g) leads to a real error for anything except substances close to water's density.
Frequently Asked Questions
Everything people ask about converting grams to fluid ounces.
How many grams are in a fluid ounce?
It depends on the substance: about 31.35 g for evaporated milk, 30.46 g for fresh milk, 29.574 g for water, 17.744 g for wheat flour, and about 25 g for sugar.
How many grams are in 12 fl oz of evaporated milk?
About 376 grams. That's very close to 12 fl oz of fresh milk (about 365.5 grams), since both kinds of milk have similar densities.
How do I convert grams to fl oz by hand?
First divide the mass in grams by the substance's density in g/cm³ to get the volume in cm³. Then divide that volume by 29.574 for US fluid ounces, or by 28.413 for UK fluid ounces.
Is a fluid ounce the same as a weight ounce?
No. A fluid ounce measures volume, while a regular (weight) ounce measures mass — the two only align numerically for substances with a density very close to water's.
What's the difference between US and UK fluid ounces?
A US fluid ounce is 29.5735 cm³, while a UK (imperial) fluid ounce is 28.4131 cm³ — the US version is about 4% larger.
How do I convert a density given in kg/m³ to g/cm³?
Multiply the density in kg/m³ by 0.001 to get the equivalent in g/cm³.
Is density in g/mL the same as density in g/cm³?
Yes. A milliliter and a cubic centimeter are the same volume, so the two units are numerically identical.
Can I enter a custom density for an ingredient that isn't listed?
Yes. Select "Other (Custom Density)" and enter your own density value in g/cm³, kg/m³, lb/ft³, lb/in³, or lb/US gal.
Why does honey weigh more per fluid ounce than water?
Honey is denser than water — its dissolved sugars pack more mass into the same volume, giving it a higher grams-per-fluid-ounce figure.
Why does flour weigh less per fluid ounce than water?
Flour is less dense than water because of the air trapped between its fine particles, so the same volume of flour weighs noticeably less than the same volume of water.
Does this calculator work in both directions?
Yes. Switch between "Grams → Fl Oz" and "Fl Oz → Grams" modes to convert in either direction.
Why do recipes sometimes list both grams and fluid ounces?
Many recipes mix weight and volume measurements for convenience, but including both makes the recipe easier to follow accurately regardless of which measuring tools you have.
Is this calculator accurate?
Yes. It uses standard reference densities for each listed ingredient and applies the exact two-step gram-to-cm³-to-fl-oz formula, or lets you enter a precise custom density.
Is it free to use?
Yes, the Grams to Fl Oz Converter is free, with no signup required.
Does it work on mobile?
Yes. The converter is fully responsive and works well on phones and tablets, right in the kitchen.
Convert Grams and Fluid Ounces Instantly
Pick your ingredient, enter a weight or volume, and get an accurate, density-based conversion in seconds.