Ounces to Grams Converter
Instantly convert ounces to grams, kilograms, milligrams, pounds, and more — with live precision control, quick presets for common weights, composite lb & oz display, and a downloadable PDF report.
Uses the exact factors 1 oz = 28.349523125 g, 1 lb = 16 oz, and 1 kg = 1000 g (avoirdupois ounce) — for reference only.
| Ounces | Grams | Kilograms | lb & oz |
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Ounces to Grams Conversion — Complete Guide for 2026
Converting ounces to grams is one of the most common small-weight conversions on the web. Home cooks follow metric recipes, bakers switch to weighing by the gram, online sellers and anyone shipping a package check postage weights, new parents translate birth weights, and hobbyists weigh parts and materials. The conversion rests on one exact international standard: 1 ounce equals exactly 28.349523125 grams.
Our free Ounces to Grams Converter performs this calculation with 0 to 8 decimal places of precision, shows the result in pounds and ounces for larger values, and converts across the full weight ladder — grams, kilograms, milligrams, pounds, stone, metric tonnes, and US tons. Quick presets, a log-scale comparison chart, a common-weights reference table, and a downloadable PDF report make it useful in the kitchen, at the shipping counter, or for project records.
How to Use the OZ to Grams Converter in 4 Steps
A complete ounce-to-gram conversion takes a few seconds. Enter a weight or tap a preset, choose your precision, and download a PDF report you can keep with a recipe, a shipping record, or a project file.
Enter Your Weight in Ounces
Type any ounce value into the input field — whole numbers or decimals such as 5.5 oz. The calculator handles everything from a fraction of an ounce (a spice or a pinch of yeast) to thousands of ounces with the same exact math, and updates the result on every keystroke.
Or Tap a Quick Preset
Common weights are one tap away: 1, 4, 8, 16, 32, and 64 oz. Each chip shows its gram value so you can read the answer before you click. The active preset stays highlighted, and typing a matching value re-selects it automatically.
Set Decimal Precision
Use the input or slider to pick 0 to 8 decimal places. Whole grams or one decimal suit cooking and postage, two decimals suit jewelry, coffee, and small parts, and three or more suit lab and technical work. The gram result follows your setting; supporting units use fixed, sensible precision.
Review & Download PDF
See your weight in grams, kilograms, milligrams, pounds, pounds-and-ounces, stone, metric tonnes, and US tons, plus a chart comparing the numbers. Click Download PDF for a two-page branded report with every conversion, the chart, and a highlighted reference table.
Why 1 Ounce = 28.349523125 Grams Exactly
The ounce you use for groceries, mail, and recipes is the avoirdupois ounce, one sixteenth of the avoirdupois pound. For centuries its metric size varied slightly from country to country, because each nation maintained its own pound standard. That changed on July 1, 1959, when the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa adopted the International Yard and Pound Agreement and defined the pound as exactly 453.59237 grams.
Divide by 16 and the ounce becomes exactly 28.349523125 grams — a terminating decimal with no hidden digits. Because the pound is defined through the kilogram, the ounce also inherited the kilogram’s 2019 redefinition in terms of the Planck constant, without its value changing at all.
Three different “ounces” to watch for
The word “ounce” covers more than one unit, and mixing them up is the most common source of error:
- Avoirdupois ounce (oz) — 28.349523125 g. The everyday weight ounce, and the one this calculator uses.
- Troy ounce (oz t) — 31.1034768 g, about 9.7% heavier. Used only for gold, silver, platinum, and other precious metals.
- Fluid ounce (fl oz) — a unit of volume, not weight: 29.5735 mL in the US and 28.4131 mL in the UK. How much a fluid ounce weighs depends entirely on what’s in the cup.
For you, this means the weight conversion itself is perfect. The only rounding in your result is the display precision you choose, and the only real uncertainty is in the scale that produced the ounce figure — or in whether the “ounces” in a recipe or label were weight or volume to begin with.
What the OZ to Grams Converter Calculates
More than a single gram figure — the tool gives you a complete weight breakdown across metric and US customary units, formatted for recipes, postage, product specs, or technical documentation.
Exact Grams (Hero Result)
The headline result multiplies your input by the exact factor 28.349523125. It is shown at the precision you select, with a one-line summary beneath it that also gives kilograms and pounds-and-ounces for a quick read.
Pounds & Ounces (Composite)
Larger ounce values are split into whole pounds plus leftover ounces — 40 oz becomes 2 lb 8 oz. This is how US package weights, produce, and birth weights are usually written, so you can match a label or a record at a glance.
Kilograms & Milligrams
The rest of the metric ladder is calculated from the same exact factor: 1 oz = 0.028349523125 kg = 28,349.523125 mg. Useful when a shipping form asks for kilograms or a supplement, lab sheet, or spec lists milligrams.
Decimal Pounds & Stone
Decimal pounds (oz ÷ 16) are what shipping calculators and spreadsheets usually want, while stone (oz ÷ 224) covers UK references. Both are exact divisions, so you can drop them straight into a form without re-entering values.
Metric Tonnes & US Tons
For bulk quantities — cases of product, inventory totals, or wholesale orders logged in ounces — the calculator also shows metric tonnes (1,000 kg) and US short tons (32,000 oz), so very large ounce figures stay readable.
Chart, Reference Table & PDF
A log-scale bar chart compares your value in oz, g, kg, mg, and lb so very different magnitudes fit on one view. A reference table of common weights highlights your input when it matches, and the two-page PDF report bundles everything for sharing or record-keeping.
Ounces to Grams Conversion Chart — Common Values
Bookmark this page or screenshot the table below for instant reference. Every value uses the exact factor 1 oz = 28.349523125 g, rounded to three decimal places for grams and five for kilograms. Everyday-item weights are typical examples and vary by brand.
| Ounces | Grams | Kilograms | lb & oz | Common Use |
|---|---|---|---|---|
| 0.25 oz | 7.087 g | 0.00709 kg | 0 lb 0.25 oz | Packet of active dry yeast |
| 0.5 oz | 14.175 g | 0.01417 kg | 0 lb 0.5 oz | About 1 tablespoon of butter |
| 1 oz | 28.350 g | 0.02835 kg | 0 lb 1 oz | Common snack or cheese serving |
| 2 oz | 56.699 g | 0.05670 kg | 0 lb 2 oz | Standard dry pasta serving |
| 3.5 oz | 99.223 g | 0.09922 kg | 0 lb 3.5 oz | ≈ 100 g; USPS First-Class letter maximum |
| 4 oz | 113.398 g | 0.11340 kg | 0 lb 4 oz | One stick of butter (¼ lb) |
| 6 oz | 170.097 g | 0.17010 kg | 0 lb 6 oz | Single-serve yogurt cup (typical) |
| 8 oz | 226.796 g | 0.22680 kg | 0 lb 8 oz | Half pound; block of cream cheese |
| 12 oz | 340.194 g | 0.34019 kg | 0 lb 12 oz | Retail bag of coffee (typical) |
| 13 oz | 368.544 g | 0.36854 kg | 0 lb 13 oz | USPS First-Class large envelope maximum |
| 16 oz | 453.592 g | 0.45359 kg | 1 lb 0 oz | Exactly 1 pound |
| 24 oz | 680.389 g | 0.68039 kg | 1 lb 8 oz | Loaf of sandwich bread (typical) |
| 32 oz | 907.185 g | 0.90718 kg | 2 lb 0 oz | 2 pounds |
| 35.274 oz | 1,000.001 g | 1.00000 kg | 2 lb 3.274 oz | ≈ 1 kilogram |
| 48 oz | 1,360.777 g | 1.36078 kg | 3 lb 0 oz | 3 pounds |
| 64 oz | 1,814.369 g | 1.81437 kg | 4 lb 0 oz | 4 pounds |
| 80 oz | 2,267.962 g | 2.26796 kg | 5 lb 0 oz | Bag of flour or sugar |
| 120 oz | 3,401.943 g | 3.40194 kg | 7 lb 8 oz | Typical newborn birth weight |
| 160 oz | 4,535.924 g | 4.53592 kg | 10 lb 0 oz | 10 pounds |
How to Convert Pounds and Ounces (Like a Birth Weight) to Grams
Many weights in the US are written in pounds and ounces — a newborn’s birth weight, a package on a shipping label, a cut of meat at the counter. Hospitals, international forms, and most of the world use grams. Converting takes one extra step: turn the whole weight into ounces first.
The two-step manual calculation
Step 1: Multiply the pounds by 16 and add the ounces to get total ounces. Step 2: Multiply total ounces by 28.349523125 to get grams. For a birth weight of 7 lb 8 oz:
120 oz × 28.349523125 = 3,401.94 g
Result: 3,401.94 g (about 3.40 kg)
Enter the total ounces in the calculator above and the hero result shows grams, while the “lb & oz” card confirms you started from the right pounds-and-ounces figure. For birth weights, 0 decimals (whole grams) matches how hospitals record them.
Common birth weights for reference
Calculated with the exact factor and rounded to two decimal places:
- 5 lb 8 oz (88 oz) = 2,494.76 g
- 6 lb 0 oz (96 oz) = 2,721.55 g
- 6 lb 8 oz (104 oz) = 2,948.35 g
- 7 lb 0 oz (112 oz) = 3,175.15 g
- 7 lb 8 oz (120 oz) = 3,401.94 g
- 8 lb 0 oz (128 oz) = 3,628.74 g
- 8 lb 8 oz (136 oz) = 3,855.54 g
- 9 lb 0 oz (144 oz) = 4,082.33 g
- 9 lb 8 oz (152 oz) = 4,309.13 g
- 10 lb 0 oz (160 oz) = 4,535.92 g
OZ to Grams — Key Conversion Numbers
The OZ to Grams Converter Is Built For You If…
Whether you’re baking from a European recipe, weighing packages for shipping, or translating a birth weight for family abroad — this calculator gives you the exact answer in seconds, with a report you can save and share.
Home Cooks & Bakers
Recipes & kitchen scalesMost recipes outside the US list ingredients in grams, while US packaging and older cookbooks use ounces. Weighing in grams is also the most reliable way to bake — it removes the guesswork of scooping flour into a cup. Convert ounce amounts to grams once and your kitchen scale does the rest.
- Convert weight ounces only — fluid ounces measure volume, not weight
- Use whole grams for most cooking, one decimal for yeast and spices
- One stick of butter = 4 oz = 113 g
- Save the PDF alongside a recipe you convert often
Sellers, Movers & Shippers
Postage & package weightsUS postage tiers are set in ounces, while international shipping forms, customs declarations, and many marketplace listings ask for grams or kilograms. Whether you’re selling items before a move or mailing packages abroad, converting accurately keeps you in the right price tier and avoids rejected labels.
- 3.5 oz ≈ 99 g — the USPS First-Class letter limit
- 13 oz ≈ 369 g — the USPS First-Class large-envelope limit
- Round package weights up, never down, before buying postage
- Check current carrier rules, as weight tiers can change
New Parents & Families
Birth & baby weightsUS hospitals usually announce birth weight in pounds and ounces, but relatives abroad, international records, and many growth charts use grams. Convert the total ounces here to share a precise figure, or to translate a metric weight from a pediatric visit into the pounds and ounces you’re used to.
- Total ounces = pounds × 16 + ounces, then convert
- 7 lb 8 oz = 120 oz = 3,402 g
- Use 0 decimals — hospitals record whole grams
- Follow your pediatrician’s guidance on growth, not conversions alone
7 Tips for Accurate OZ to Grams Conversions
The math is a single multiplication, but mixing up weight and volume, rounding too aggressively, or using the wrong kind of ounce causes real mistakes — collapsed cakes, wrong postage, or mispriced metal. These rules keep every conversion trustworthy.
Don’t Confuse Ounces with Fluid Ounces
An ounce (oz) is weight; a fluid ounce (fl oz) is volume. Only for water does a US fluid ounce weigh close to an ounce (about 29.6 g). A fluid ounce of honey is much heavier and one of flour much lighter. If a recipe or label says “fl oz,” this is the wrong converter.
Don’t Round 28.35 g Up to 30 g
Treating an ounce as 30 g overstates the weight by almost 6% — enough to throw off a bread recipe or push a package into the next postage tier. Rounding down to 28 g is closer (about 1.2% low). For anything that matters, use 28.35 g or the exact factor.
Weigh in Grams When You Can
Most digital kitchen and postal scales switch between ounces and grams with one button. Grams give finer steps (1 g vs. 0.1 oz, which is about 2.8 g) and avoid conversion entirely. Use the tare button to zero out the bowl or box first.
Use Troy Ounces for Gold and Silver
Precious metals are weighed in troy ounces of 31.1035 g, about 9.7% heavier than the everyday ounce. Converting a coin or bar with this calculator would understate its gram weight and value. For bullion, use a troy-ounce converter.
Match Precision to Your Use Case
Whole grams are plenty for cooking and postage. One decimal suits yeast, spices, and coffee. Two decimals suit jewelry and small parts, and three or more only make sense for lab work with a scale that precise. Extra decimals never make a rough reading more accurate.
Convert Pounds & Ounces in Two Steps
For a figure like 3 lb 5 oz, first convert to total ounces (3 × 16 + 5 = 53 oz), then to grams (1,502.52 g). Converting the pounds and ounces separately and adding them works too, but it’s easy to forget one part.
Memorize a Few Anchors for Mental Math
1 oz ≈ 28 g, 4 oz ≈ 113 g, 8 oz ≈ 227 g, 1 lb ≈ 454 g, and 100 g ≈ 3.5 oz. With these you can sanity-check any recipe or label in your head and catch a result that’s obviously off.
OZ to Grams Converter — Frequently Asked Questions
Everything you need to know about converting ounces to grams, the difference between weight, fluid, and troy ounces, and how to apply this calculator to recipes, packages, and birth weights.
Multiply the number of ounces by 28.349523125. That factor is exact: 1 avoirdupois ounce is defined as exactly 28.349523125 grams. For example, 8 oz × 28.349523125 = 226.796185 g.
The value comes from the 1959 International Yard and Pound Agreement, which fixed the pound at 453.59237 g; an ounce is exactly one sixteenth of that. Our calculator uses the full factor and lets you display 0 to 8 decimal places.
The exact formula is: grams = ounces × 28.349523125. To go the other way: ounces = grams ÷ 28.349523125, which is the same as grams × 0.035274 (rounded).
Quick references: 1 oz ≈ 28.35 g, 4 oz ≈ 113.40 g, 8 oz ≈ 226.80 g, 16 oz (1 lb) ≈ 453.59 g, and 100 g ≈ 3.53 oz.
The International Yard and Pound Agreement of 1959 defined the avoirdupois pound as exactly 453.59237 grams. Because a pound contains exactly 16 ounces, one ounce is 453.59237 ÷ 16 = 28.349523125 grams, with no further digits.
This single definition is used in the United States, the United Kingdom, Canada, Australia, New Zealand, and South Africa.
Using the exact factor:
1 oz = 28.35 g · 2 oz = 56.70 g · 3 oz = 85.05 g · 4 oz = 113.40 g · 5 oz = 141.75 g · 6 oz = 170.10 g · 8 oz = 226.80 g · 10 oz = 283.50 g · 12 oz = 340.19 g · 16 oz = 453.59 g · 20 oz = 566.99 g · 32 oz = 907.18 g.
Enter any exact value in the calculator above for up to 8 decimal places.
Divide grams by 28.349523125, or multiply by 0.035274. For example:
10 g = 0.35 oz · 50 g = 1.76 oz · 100 g = 3.53 oz · 250 g = 8.82 oz · 500 g = 17.64 oz · 1,000 g (1 kg) = 35.27 oz.
This converter takes ounces as its input; to check a gram value, enter the ounce figure you calculated and confirm the gram result matches.
1 ounce equals exactly 28.349523125 grams. For everyday use it is usually rounded to 28.35 g, and many US food labels round a 1 oz serving to 28 g.
Rounding up to 30 g is a convenient kitchen shortcut, but it overstates the weight by almost 6%, so avoid it for baking or anything that needs accuracy.
No. An ounce (oz) measures weight; a fluid ounce (fl oz) measures volume. A US fluid ounce is 29.5735 milliliters, and a UK imperial fluid ounce is 28.4131 milliliters.
Only for water and water-like liquids does a US fluid ounce weigh close to 1 oz (about 29.6 g, or 1.04 oz). For flour, sugar, honey, or oil, a fluid ounce by volume and an ounce by weight are very different, so don’t use this calculator to convert fluid ounces.
It depends on the ingredient, because a cup is a volume and grams are a weight. Typical figures: a US cup of water weighs about 237 g, granulated sugar about 200 g, and all-purpose flour roughly 120–130 g depending on how it’s scooped.
That variation is why many bakers weigh ingredients in grams. If a recipe gives ounces by weight, convert them here; if it gives cups or fluid ounces, use an ingredient-specific chart.
The everyday avoirdupois ounce is 28.349523125 g. The troy ounce, used only for gold, silver, platinum, and other precious metals, is 31.1034768 g — about 9.7% heavier. Bullion prices are quoted per troy ounce.
This calculator uses the avoirdupois ounce, so don’t use it to value precious metals.
There are exactly 16 ounces in a pound, so 1 lb = 16 oz = 453.59237 g. To convert ounces to pounds and ounces, divide by 16: the whole number is pounds and the remainder is ounces.
For example, 40 oz ÷ 16 = 2 with 8 left over, so 40 oz = 2 lb 8 oz. The calculator shows this format automatically in the “lb & oz” summary card.
First convert to total ounces by multiplying the pounds by 16 and adding the ounces, then multiply by 28.349523125. For example, 7 lb 8 oz = (7 × 16) + 8 = 120 oz, and 120 × 28.349523125 = 3,401.94 g.
Common birth weights: 6 lb = 2,721.55 g, 7 lb = 3,175.15 g, 7 lb 8 oz = 3,401.94 g, 8 lb = 3,628.74 g, and 9 lb = 4,082.33 g.
The calculator uses the exact factor 1 oz = 28.349523125 g with double-precision floating-point arithmetic, accurate to about 15 significant digits. Display precision is adjustable from 0 to 8 decimal places.
In practice your scale is the limiting factor: most digital kitchen scales read in 1 g or 0.1 oz steps, and jewelry scales in 0.01 g steps.
Accuracy note: The HomeExpertly Ounces to Grams Converter uses the exact international conversion factor of 1 avoirdupois ounce = 28.349523125 grams, derived from the pound as defined by the 1959 International Yard and Pound Agreement and recognized by the U.S. National Institute of Standards and Technology (NIST) and the International Bureau of Weights and Measures (BIPM). All calculations are mathematically precise to the decimal precision you select (up to 8 places). However, results are for informational and reference purposes only. This calculator converts weight ounces only — it does not convert fluid ounces (volume) or troy ounces (precious metals). Everyday-item weights and postal limits shown on this page are typical figures that vary by brand and may change; always confirm current carrier rules. For applications where weight accuracy is critical — including but not limited to medication or infant-formula preparation, medical records, precious-metal transactions, legal-for-trade sales, customs declarations, or scientific work — always verify your conversions independently and use calibrated, certified weighing equipment. Display rounding at lower precision levels (0–3 decimal places) may introduce minor differences from the mathematically exact result. HomeExpertly is not responsible for any consequences arising from the use of these conversions, including but not limited to recipe failures, postage shortfalls, or pricing errors. When in doubt, weigh twice, use the highest available precision, and consult a qualified professional.