Ounces to Grams Conversion Guide: oz to g Calculator
Converting ounces to grams is essential for cooking, baking, and following recipes from different countries. This guide covers the conversion formulas, provides handy charts, and explains the differences between UK and US measurements.
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The Conversion Formula
Grams to Ounces: ounces = grams ÷ 28.3495
1 ounce = 28.3495 grams
1 ounce ≈ 28 grams (for cooking)
Quick Reference: Ounces to Grams Chart
| Ounces (oz) | Grams (g) | Common Use |
|---|---|---|
| ½ oz | 14 g | Herbs, spices |
| 1 oz | 28 g | Chocolate square |
| 2 oz | 57 g | Cheese portion |
| 3 oz | 85 g | Pasta serving |
| 4 oz | 113 g | Quarter pound, butter stick |
| 5 oz | 142 g | Yogurt pot |
| 6 oz | 170 g | Fish fillet |
| 8 oz | 227 g | Half pound |
| 12 oz | 340 g | Tin of beans |
| 16 oz | 454 g | One pound |
Baking Measurements: Ounces to Grams
For baking, precise measurements are crucial. Here are common baking ingredient conversions:
| Ingredient | Ounces | Grams | Cups (approx) |
|---|---|---|---|
| Flour (plain/SR) | 4 oz | 113 g | 1 cup |
| Flour | 8 oz | 227 g | 2 cups |
| Sugar (caster) | 7 oz | 200 g | 1 cup |
| Sugar (icing) | 4 oz | 113 g | 1 cup |
| Butter | 4 oz | 113 g | ½ cup |
| Butter | 8 oz | 227 g | 1 cup |
| Chocolate chips | 6 oz | 170 g | 1 cup |
| Oats | 3 oz | 85 g | 1 cup |
| Cocoa powder | 3 oz | 85 g | 1 cup |
Understanding Ounces vs Fluid Ounces
Important Distinction
Ounces (oz) measure weight (mass)
Fluid ounces (fl oz) measure volume
They're NOT directly interchangeable! 8 oz of flour does not equal 8 fl oz of flour.
| Measurement | UK | US |
|---|---|---|
| 1 fluid ounce | 28.4 ml | 29.6 ml |
| 1 cup (volume) | 284 ml (10 fl oz) | 237 ml (8 fl oz) |
| 1 pint | 568 ml | 473 ml |
Pounds and Ounces to Grams
To convert pounds and ounces to grams:
Total grams = (pounds × 453.592) + (ounces × 28.3495)
| Pounds & Ounces | Grams |
|---|---|
| ¼ lb (4 oz) | 113 g |
| ½ lb (8 oz) | 227 g |
| ¾ lb (12 oz) | 340 g |
| 1 lb (16 oz) | 454 g |
| 1½ lb (24 oz) | 680 g |
| 2 lb (32 oz) | 907 g |
Grams to Ounces Conversion
| Grams | Ounces | Approximate |
|---|---|---|
| 10 g | 0.35 oz | ⅓ oz |
| 25 g | 0.88 oz | ≈ 1 oz |
| 50 g | 1.76 oz | 1¾ oz |
| 100 g | 3.53 oz | 3½ oz |
| 150 g | 5.29 oz | 5¼ oz |
| 200 g | 7.05 oz | 7 oz |
| 250 g | 8.82 oz | ≈ 9 oz |
| 500 g | 17.64 oz | 1 lb 1½ oz |
| 1000 g (1 kg) | 35.27 oz | 2 lb 3 oz |
Common Recipe Conversions
British Recipes Using Ounces
Victoria Sponge (Classic Recipe)
- 6 oz (170 g) self-raising flour
- 6 oz (170 g) caster sugar
- 6 oz (170 g) butter
- 3 eggs
Shortbread
- 6 oz (170 g) plain flour
- 4 oz (113 g) butter
- 2 oz (57 g) caster sugar
American Recipe Conversions
American recipes often use cups and fluid ounces. Here's how common US measurements convert:
| US Measure | Grams (flour) | Grams (sugar) | Grams (butter) |
|---|---|---|---|
| ¼ cup | 31 g | 50 g | 57 g |
| ⅓ cup | 42 g | 67 g | 76 g |
| ½ cup | 63 g | 100 g | 113 g |
| ¾ cup | 94 g | 150 g | 170 g |
| 1 cup | 125 g | 200 g | 227 g |
Troy Ounces vs Avoirdupois Ounces
There are actually two types of ounces:
- Avoirdupois ounce: 28.35 grams (used for food, everyday items)
- Troy ounce: 31.10 grams (used for precious metals like gold and silver)
All cooking and food measurements use avoirdupois ounces.
Tips for Accurate Baking
- Use a digital scale: More accurate than volume measures
- Weigh in grams: More precise than ounces for small amounts
- Tare your bowl: Zero the scale with the bowl on before adding ingredients
- Check recipe origin: US and UK cups differ in size
- Round sensibly: For baking, round to nearest 5 grams
Small Measurements for Spices
For small amounts like spices, you might need these conversions:
| Measurement | Grams |
|---|---|
| 1/16 oz | 1.8 g |
| ⅛ oz | 3.5 g |
| ¼ oz | 7 g |
| ⅓ oz | 9.5 g |
| ½ oz | 14 g |
| ¾ oz | 21 g |
Need Quick Conversions?
Use our Ounces to Grams Converter for instant, accurate results!
Conclusion
Key conversion facts to remember:
- 1 oz = 28 grams (approximately, for cooking)
- 1 oz = 28.3495 grams (exact)
- 16 oz = 1 pound = 454 grams
- Ounces measure weight; fluid ounces measure volume
- Use a digital scale for the most accurate baking results
With these conversions, you'll be able to follow any recipe regardless of whether it uses metric or imperial measurements!
Imperial vs Metric: Why the UK Uses Both Systems
The United Kingdom occupies a unique position in the world of measurement, officially using the metric system since 1965 while simultaneously retaining deep cultural attachment to imperial units. This dual system means that UK residents regularly need to convert between ounces and grams, particularly in cooking, food shopping, and following recipes from different sources.
Under EU regulations adopted into UK law, all pre-packaged food sold in the UK must display metric measurements (grams, kilograms). However, imperial equivalents can also be shown alongside metric figures, and many traditional butchers, bakers, and market stall holders still think and communicate in pounds and ounces. In September 2022, the UK government confirmed that imperial measurements could be used as the primary or sole measurement for trade, though most businesses continue to use metric as standard.
Understanding the difference between weight and mass matters for precise conversions. In everyday cooking, we use both ounces (weight) and fluid ounces (volume) without always distinguishing between them. One fluid ounce of water weighs approximately one ounce, but this relationship breaks down for other liquids. Olive oil, for example, is lighter than water, so a fluid ounce of oil weighs less than a standard ounce. For accurate baking, always use weight measurements (grams or ounces) rather than volume (cups or fluid ounces) when possible.
Food Labelling and Portion Sizes in the UK
UK food labelling regulations require nutritional information to be displayed per 100 grams (or 100 millilitres for liquids), making metric understanding essential for comparing products. Many packaging sizes reflect metric standards: 500g packets of pasta, 250g blocks of butter, 1kg bags of flour. However, some traditional products still use imperial-origin sizes, like the 454g (1 pound) tin or the 568ml (1 pint) milk bottle.
The NHS recommends daily intake amounts in grams: no more than 6g of salt, at least 30g of fibre, no more than 30g of free sugars, and a recommended 0.75g of protein per kilogram of body weight. Being comfortable with gram measurements helps you make informed dietary choices and accurately track your nutritional intake.
Quick Conversion Tips for the Kitchen
For everyday cooking, memorising a few key benchmarks makes conversions intuitive: 1 oz is roughly 28g (think of it as about 30g for quick mental maths), 4 oz is about 113g (roughly a quarter pound), and 8 oz is about 227g (roughly half a pound). For baking, where precision matters more, always use exact conversions and a digital kitchen scale with both metric and imperial settings.
When following American recipes, be aware that US cups are volume measurements that vary by ingredient density. A cup of flour weighs about 125g, a cup of sugar about 200g, and a cup of butter about 227g. British recipes increasingly use grams for all ingredients, which is more precise and reproducible. If converting a family recipe from ounces to grams, write down the converted measurements for future use to save time.
Why do UK recipes still use ounces?
Many cherished family recipes and older British cookbooks were written using imperial measurements. While modern UK recipe books and websites predominantly use metric, the cultural tradition of ounces and pounds persists, especially among older generations. BBC Good Food and similar sites now provide both metric and imperial measurements to accommodate all readers.
Is an ounce the same everywhere in the world?
The avoirdupois ounce (28.3495g), used for food and general weighing, is standardised internationally. However, the troy ounce (31.1035g) is used exclusively for precious metals like gold and silver. The US fluid ounce (29.57ml) and the imperial fluid ounce (28.41ml) also differ slightly, which can cause confusion with liquid measurements in recipes from different countries.
What is the most accurate way to measure ingredients at home?
A digital kitchen scale measuring in 1-gram increments is the most accurate tool for home cooking. These are available for under £10 and eliminate the guesswork of volume measurements. For very small amounts like spices (under 5g), measuring spoons are acceptable as even good scales can be inaccurate at very low weights. Always use the tare function to zero your scale with the container on it before adding ingredients.
Emma Thompson
Senior Content Editor
Emma is a senior content editor with a background in financial journalism. She specialises in making UK regulations and calculator tools understandable for consumers, working closely with qualified professionals to ensure accuracy.