Ounces to Grams Conversion
Ounces to Grams Calculator
Ounces to Grams Conversion
Convert ounces to grams instantly with the calculator above, or browse the complete table below for every common ounce value. Because ounces and grams both measure mass, the conversion is fixed by international agreement — no density, no ingredient, no guesswork. One ounce equals exactly 28.349523125 grams, a relationship set by the 1959 International Yard and Pound Agreement and maintained today by NIST. So 1 oz = 28.35 g, 8 oz = 226.80 g, and 16 oz (one pound) = 453.59 g.
Ounces to Grams at a Glance
How to Convert Ounces to Grams
Step 1: Use the Exact Conversion Factor
Ounces and grams both measure mass — how much matter an object contains — so the conversion is a single, fixed multiplication. There’s no density variable, no ingredient adjustment, and no rounding ambiguity. The international relationship is:
This factor was set by the 1959 International Yard and Pound Agreement signed by the US, UK, Australia, Canada, New Zealand, and South Africa, and is published by NIST as part of Handbook 44. It applies wherever the standard (“avoirdupois”) ounce is used — which is everywhere outside the precious-metals trade.
Step 2: Apply the Formula
To turn ounces into grams, multiply by the grams-per-ounce factor:
For example, to convert 8 ounces to grams:
That’s why an 8-ounce stick-and-a-half of butter weighs 227 grams on a metric scale, why a “half pound” of deli meat is labelled 227 g in many countries, and why 8 oz of water is exactly 1 US cup (since water’s density makes mass and volume align at 1 g per mL).
Quick mental math: Multiply ounces by 28 for a fast estimate, then add about 1.2 % for accuracy. For 8 oz: 8 × 28 = 224, plus 1.2 % ≈ 226.7. Easier in the supermarket than dividing in your head.
Step 3: Worked Example — 4 Ounces to Grams
Goal: Convert 4 ounces (one US stick of butter) to grams.
1. Identify the conversion factor:
2. Apply the formula:
3. Calculate the result:
Answer: 4 oz of butter equals about 113.40 g — which is why most metric butter packaging rounds to 113 g per stick.
Step 4: Reverse-Check Your Result
To verify, divide your gram result by 28.349523125 and confirm you get back the original ounce value:
Small differences may appear if you used a rounded ounce or gram value — the calculator at the top of this page uses the full-precision factor and will round-trip without error.
Step 5: Choose the Correct Ounce
“Ounce” is one of the most overloaded words in measurement. Three different ounces are still in active use, and they each give a different gram equivalent:
- Standard ounce (avoirdupois): 28.349523125 g. The default for food, postage, retail packaging, and nutrition labels. Whenever a recipe or label says “oz” without qualification, this is the unit. 8 oz = 226.80 g.
- Troy ounce: 31.1034768 g. Used for gold, silver, platinum, and palladium. About 9.7 % heavier than the standard ounce, so 8 troy oz = 248.83 g.
- Fluid ounce: a volume unit (≈ 29.57 mL in the US, ≈ 28.41 mL in the UK), not a mass unit. Never use fluid ounces in an ounce-to-gram weight conversion.
Rounding rules used on this page: Grams are shown to two decimal places for everyday use and four decimals for precision tasks. The full-precision factor (28.349523125) is exact — any rounding error in the result comes from rounding the gram output, not from the conversion itself.
Ounces to Grams Quick Reference Chart
Complete Ounces to Grams Conversion Table
This table covers the most-searched ounce amounts and their exact gram equivalents, plus the kilogram and pound equivalents for larger values. For any value not listed, use the calculator at the top of the page or click through to a dedicated conversion page.
| Ounces | Grams (g) | Kilograms (kg) | Pounds | View page |
|---|---|---|---|---|
| 1 oz | 28.3495 g | 0.0283 kg | 0.0625 lb | View → |
| 2 oz | 56.6990 g | 0.0567 kg | 0.1250 lb | View → |
| 3 oz | 85.0486 g | 0.0850 kg | 0.1875 lb | View → |
| 4 oz | 113.3981 g | 0.1134 kg | 0.2500 lb | View → |
| 5 oz | 141.7476 g | 0.1417 kg | 0.3125 lb | View → |
| 6 oz | 170.0971 g | 0.1701 kg | 0.3750 lb | View → |
| 7 oz | 198.4467 g | 0.1984 kg | 0.4375 lb | View → |
| 8 oz (½ lb) | 226.7962 g | 0.2268 kg | 0.5000 lb | View → |
| 9 oz | 255.1457 g | 0.2551 kg | 0.5625 lb | View → |
| 10 oz | 283.4952 g | 0.2835 kg | 0.6250 lb | View → |
| 12 oz (¾ lb) | 340.1943 g | 0.3402 kg | 0.7500 lb | View → |
| 14 oz | 396.8933 g | 0.3969 kg | 0.8750 lb | View → |
| 16 oz (1 lb) | 453.5924 g | 0.4536 kg | 1.0000 lb | View → |
| 18 oz | 510.2914 g | 0.5103 kg | 1.1250 lb | View → |
| 20 oz | 566.9905 g | 0.5670 kg | 1.2500 lb | View → |
| 24 oz (1½ lb) | 680.3885 g | 0.6804 kg | 1.5000 lb | View → |
| 28 oz | 793.7866 g | 0.7938 kg | 1.7500 lb | View → |
| 32 oz (2 lb) | 907.1848 g | 0.9072 kg | 2.0000 lb | View → |
| 40 oz | 1133.9809 g | 1.1340 kg | 2.5000 lb | View → |
| 48 oz (3 lb) | 1360.7771 g | 1.3608 kg | 3.0000 lb | View → |
| 56 oz | 1587.5733 g | 1.5876 kg | 3.5000 lb | View → |
| 64 oz (4 lb) | 1814.3695 g | 1.8144 kg | 4.0000 lb | View → |
| 80 oz (5 lb) | 2267.9619 g | 2.2680 kg | 5.0000 lb | View → |
| 96 oz (6 lb) | 2721.5542 g | 2.7216 kg | 6.0000 lb | View → |
| 128 oz (8 lb) | 3628.7390 g | 3.6287 kg | 8.0000 lb | View → |
Units of Measurement
Ounces and grams are both units of mass — they measure how much matter an object contains, not how much space it takes up. That’s why converting between them is a fixed multiplication: the ingredient or material doesn’t change the answer. An ounce of feathers and an ounce of lead both weigh exactly the same.
What is an Ounce?
Standard ounce (avoirdupois)
= 28.349523125 g (exact). The default ounce for food, postage, and consumer goods. 1 oz = 28.35 g.
Troy ounce
= 31.1034768 g. Used for gold, silver, platinum, and palladium. About 9.7 % heavier than the standard ounce.
Apothecaries’ ounce
= 31.1034768 g. Historically used in pharmacy. Equal to the troy ounce; rarely used today.
Fluid ounce
A volume unit (≈ 29.57 mL US, 28.41 mL UK), not a mass unit. Don’t confuse it with the weight ounce.
What is a Gram?
Why the Conversion is Exact
Ounces Converted to Other Weight Units
| Unit | Equivalent in Ounces |
|---|---|
| 1 gram (g) | 0.0353 oz |
| 1 milligram (mg) | 0.000035 oz |
| 1 kilogram (kg) | 35.2740 oz |
| 1 pound (lb) | 16 oz |
| 1 stone (st) | 224 oz |
| 1 short ton (US) | 32,000 oz |
| 1 long ton (UK) | 35,840 oz |
| 1 metric ton (t) | 35,274 oz |
| 1 troy ounce (oz t) | 1.0971 oz |
| 1 dram (dr) | 0.0625 oz (1/16 oz) |
| 1 grain (gr) | 0.002286 oz |
| 1 pennyweight (dwt) | 0.054857 oz |
| 1 carat (ct) | 0.007055 oz |
Grams Converted to Other Weight Units
| Unit | Equivalent in Grams |
|---|---|
| 1 ounce (oz) | 28.349523125 g |
| 1 troy ounce (oz t) | 31.1034768 g |
| 1 pound (lb) | 453.59237 g |
| 1 stone (st) | 6,350.29318 g |
| 1 milligram (mg) | 0.001 g |
| 1 centigram (cg) | 0.01 g |
| 1 decigram (dg) | 0.1 g |
| 1 dekagram (dag) | 10 g |
| 1 hectogram (hg) | 100 g |
| 1 kilogram (kg) | 1,000 g |
| 1 metric ton (t) | 1,000,000 g |
| 1 dram (dr) | 1.7718 g |
| 1 grain (gr) | 0.06479891 g |
| 1 pennyweight (dwt) | 1.55517384 g |
| 1 carat (ct) | 0.2 g |
Real-World Reference: What Do These Weights Look Like?
Numbers on a scale are easier to picture when you can compare them to everyday objects. Use this reference whenever you don’t have a scale handy and need to estimate a weight from sight or feel.
Popular Ounces to Grams Conversions
These are the ounce amounts our visitors look up most often. Each link opens a dedicated calculator with the precise gram value, kilogram equivalent, troy-ounce equivalent, full multi-unit breakdown, and printable chart.
More Frequently Searched Ounce Amounts
Frequently Asked Questions
How many grams are in an ounce?
One ounce equals exactly 28.349523125 grams. This value was set by the 1959 International Yard and Pound Agreement and is recognised by NIST and every major standards body worldwide. For everyday use, round to 28.35 g.
How many grams are in 8 ounces?
8 ounces equals 226.7962 grams (or about 226.80 g for practical use). This is the standard half-pound measurement, equivalent to two US sticks of butter or one cup of water by weight.
How many grams are in 16 ounces (one pound)?
16 ounces equals exactly 453.59237 grams, which is one pound (lb). So 1 kg is approximately 2.2046 lb, and 1 lb is approximately 0.4536 kg.
What is the formula to convert ounces to grams?
Multiply the number of ounces by 28.349523125 to get grams. To go the other way, divide grams by 28.349523125, or equivalently multiply by 0.03527396195.
Does the ounces-to-grams conversion change with the ingredient?
No. Both ounces and grams measure mass, so the conversion is fixed regardless of what is being weighed. 4 ounces of flour, water, or lead all equal 113.40 grams. Ingredient density only matters when converting between mass and volume — for example, ounces to cups or ounces to tablespoons.
What’s the difference between a standard ounce and a troy ounce?
A standard (avoirdupois) ounce is 28.349523125 g and is used for food, postage, and consumer goods. A troy ounce is 31.1034768 g, about 9.7 % heavier, and is used exclusively for precious metals like gold, silver, platinum, and palladium. Bullion prices and coin specifications are always quoted in troy ounces.
Is a fluid ounce the same as an ounce?
No. A fluid ounce (fl oz) is a unit of volume, while an ounce (oz) is a unit of mass. Confusingly, they share a name because, for water specifically, 1 fluid ounce of water happens to weigh approximately 1 ounce. For any other substance the two values differ. Never use fluid ounces in an ounces-to-grams conversion.
How do I quickly estimate ounces to grams in my head?
Multiply ounces by 28 for a fast estimate, then add about 1.2 % for accuracy. For example, 8 oz × 28 = 224, plus 1.2 % ≈ 226.7 — very close to the exact 226.80 g.
What’s the most accurate way to weigh ounces?
Use a calibrated digital kitchen, postal, or pocket scale that lets you toggle between ounces and grams. Setting the display to grams and converting upward removes one source of rounding error. Avoid converting through volume units like cups or teaspoons — those readings depend on packing and humidity and introduce error every time.
Are these conversions valid in the UK, Australia, and Canada?
Yes. The 1959 International Yard and Pound Agreement was signed by the US, UK, Australia, Canada, New Zealand, and South Africa, so all six countries use exactly the same definition: 1 ounce = 28.349523125 grams. The conversion is identical wherever the standard ounce is used.