Last updated: February 2026

Grams to Ounces Converter

Convert between grams and ounces (both directions)

About This Converter

This converter is part of UK Calculator’s maths and conversion tools. Perfect for cooking, baking, postal weights, and any situation where you need to convert between metric and imperial weight measurements.

Why Use UK Calculator?

  • Accurate: Uses the exact conversion factor (1 oz = 28.349523125 g)
  • Free: No registration required
  • Privacy-focused: All calculations in your browser
  • Mobile-friendly: Works on all devices

Related Calculators

Grams to Ounces: A Complete UK Conversion Guide

The gram (g) and the ounce (oz) are two of the most commonly used units of weight in the UK. While grams are the standard metric unit used on food packaging and in modern recipes, ounces remain deeply embedded in British cooking traditions, postal services, and everyday conversation. This guide provides comprehensive conversion information for UK users.

The Exact Conversion

1 ounce (oz) = 28.349523125 grams (g)

1 gram (g) = 0.035274 ounces (oz)

Common Cooking Conversions Table

This table provides the most commonly used conversions for UK cooking and baking. Values are rounded to practical amounts:

GramsOuncesCommon Use
10 g0.35 ozTeaspoon of spice
25 g0.88 oz (~1 oz)Tablespoon of butter
50 g1.76 oz (~2 oz)Small portion of cheese
100 g3.53 oz (~3.5 oz)Standard chocolate bar
150 g5.29 oz (~5 oz)Chicken breast
200 g7.05 oz (~7 oz)Standard tin of tuna
250 g8.82 oz (~9 oz)Block of butter
350 g12.35 oz (~12 oz)Standard flour bag (small)
450 g15.87 oz (~1 lb)One pound equivalent
500 g17.64 ozPack of mince
1,000 g (1 kg)35.27 oz (2 lb 3 oz)Bag of sugar

Ounces to Grams: Reverse Conversion Table

OuncesGramsPounds
1 oz28.35 g1/16 lb
2 oz56.70 g1/8 lb
4 oz113.40 g1/4 lb
6 oz170.10 g3/8 lb
8 oz226.80 g1/2 lb
12 oz340.19 g3/4 lb
16 oz453.59 g1 lb

Weight Measurement History in the UK

The United Kingdom has a fascinating history with weight measurement. The avoirdupois system (the basis for ounces and pounds used today) was standardised in England in 1588 by Queen Elizabeth I. The word “avoirdupois” comes from the Anglo-Norman French phrase meaning “goods of weight”. For centuries, this was the only system used in British trade and daily life.

The metric system began to be adopted in the UK with the Weights and Measures Act 1985, and EU directives from the 1990s required metric measurements for packaged goods. Since 1 January 2000, goods sold loose (such as fruit, vegetables, and meat at markets) must be priced and sold in metric units, though traders may display imperial equivalents alongside. Despite this, many UK residents continue to think in imperial terms, particularly for body weight (stone and pounds) and cooking (ounces).

UK Postal Weight Limits

Royal Mail uses grams and kilograms for postal weights. Standard letter: up to 100 g. Large letter: up to 750 g. Small parcel: up to 2 kg. Medium parcel: up to 20 kg. If you are weighing items for posting and your scales show ounces, this converter will help you determine the correct postal weight band and associated cost.

Cooking Tips: When Precision Matters

For everyday cooking (soups, stews, casseroles), approximate conversions are perfectly fine. However, for baking, where precise measurements affect the chemistry of the recipe, always use grams with a digital scale. A difference of even 10-15 grams in flour can affect the texture of bread or cakes. Many professional bakers and the BBC Good Food team recommend using grams exclusively for baking recipes, as cups and ounces introduce too much variability.

If you are converting a traditional recipe from ounces to grams, round to the nearest 5 grams for convenience without significantly affecting the result. For example, 6 oz of flour converts to 170.1 g, which you can safely round to 170 g.

Exact Conversion
Secure & Private
190+ Calculators
Always Free

Sources & Methodology

Written by: Mustafa Bilgic

Data sources: BIPM (International Bureau of Weights and Measures), UK Weights and Measures Act 1985, NIST

Last updated:

Calculation Method: Uses the exact conversion factor: 1 avoirdupois ounce = 28.349523125 grams, as defined by international agreement. No rounding is applied in the calculation itself.

Disclaimer: This converter uses the avoirdupois ounce (standard for food, postage, and general use). For precious metals, use the troy ounce (31.1035 g). For fluid measurements, use a volume converter rather than a weight converter.

Related Calculators

Fractions Calculator

Fraction operations

Square Metres Calculator

Area conversion

Calorie Calculator

Daily calorie intake

BMI Calculator

Body mass index

Percentage Calculator

Percentage calculations

Expert Reviewed — Uses internationally standardised conversion factors. Last verified: February 2026.

Pro Tips
  • For baking, always use grams with a digital scale for precision
  • Round to the nearest 5g when converting recipes from ounces
  • Remember: fluid ounces measure volume, not weight
  • Use the reverse conversion for American recipes
Common Questions

Is this for avoirdupois or troy ounces?

Avoirdupois (standard ounces for food and general use). Troy ounces are for precious metals.

Can I convert kilograms too?

Yes, the results show kilograms as well as grams, ounces, and pounds.

People Also Ask

It depends on the ingredient. A tablespoon of sugar is about 12g, flour about 8g, butter about 14g, and water about 15g. Tablespoons measure volume, so the weight varies by density.

Yes, the avoirdupois ounce (used for weight) is the same in both the UK and the US: 28.3495 grams. However, fluid ounces differ: 1 UK fl oz = 28.41 ml, while 1 US fl oz = 29.57 ml.

MB

Mustafa Bilgic - UK Calculator Editorial Team

Our converters use exact internationally standardised conversion factors. Learn more about our team.

Embed This Converter