Ounces to Grams Converter
Convert ordinary avoirdupois ounces or troy ounces to grams, or enter grams to convert in reverse.
Ready to export the current conversion.
Conversion inputs
Use troy ounces for precious metals; use avoirdupois ounces for ordinary goods and recipes.
Required when editing ounces. Enter a nonnegative decimal using a period.
Edit this field to convert grams back to the selected ounce type.
Live result
Nearby conversion table
| Ounces | Grams | Kilograms | Avoirdupois pounds |
|---|---|---|---|
| 1 oz | 28.349523 g | 0.028350 kg | 0.0625 lb |
Rows are centered around the current ounce value and use the same canonical conversion model as the live result and workbook.
How to use the ounces to grams calculator
What this calculator does. This tool converts mass between ounces and grams. It supports the common international avoirdupois ounce used for food, parcels, household goods, and most everyday measurements, plus the troy ounce used for precious metals. It also reports kilograms and avoirdupois pounds for quick context. The conversion is an exact unit identity when the selected ounce definition is known; it does not estimate density, volume, shipping price, nutritional content, or the accuracy of the scale that produced the measurement.
When to use it. Use it when translating a recipe written in ounces into metric mass, checking a product specification, converting a parcel weight, comparing laboratory notes, or converting a gold or silver quotation expressed in troy ounces. Remember that a fluid ounce measures volume and is not interchangeable with the mass ounce used here.
How to calculate. The calculator opens with a ready-to-use demonstration of 5 avoirdupois ounces, equal to 141.747615625 grams, and its Excel workbook is immediately available.
- Choose Ounce type. Select “Avoirdupois ounce (oz)” for ordinary mass or “Troy ounce (oz t)” for precious metals.
- Replace the demonstration value in Ounces, or edit Grams to calculate in reverse. The last field you edit controls the direction.
- Read Equivalent mass, then review Selected ounces, Kilograms, Avoirdupois pounds, Conversion factor, the formula line, and the nearby conversion table.
- Select Download Excel to create a validated workbook from the current values. Reset clears the demonstration data and disables export until a complete valid value is entered again.
Input guide. Ounce type is required and accepts one of two definitions. Avoirdupois uses exactly 28.349523125 grams per ounce; troy uses exactly 31.1034768 grams per troy ounce. Choosing troy increases the gram result for the same numeric ounce value. A common mistake is using troy ounces for food or ordinary retail goods. Ounces accepts a required nonnegative decimal such as 5, 0.5, or 14. Use a period as the decimal separator; commas, scientific notation, unit text, negative numbers, NaN, and infinity are rejected rather than silently reinterpreted. Increasing ounces increases every mass output proportionally. Grams follows the same accepted numeric format and can be edited instead, for example 100. When grams is the active source, the calculator divides by the selected factor to recover ounces. The two small unit selectors are fixed labels, not alternative conversion modes.
Output guide. Equivalent mass is the main gram value when ounces drive the calculation. Selected ounces shows the normalized amount in the chosen ounce definition. Kilograms divides grams by 1,000. Avoirdupois pounds divides the avoirdupois-ounce equivalent by 16, even when the input originated as troy ounces, so it remains a familiar ordinary-pound comparison. Conversion factor displays the exact grams-per-selected-ounce constant. The formula line shows the operation actually used. The nearby table gives half, equal, double, and tenfold ounce values around the current result. Zero is valid and represents zero mass; very large finite values are accepted only while every derived result remains finite.
Worked example. With the startup settings, Ounce type is avoirdupois and Ounces is 5. Multiply 5 by 28.349523125 to obtain 141.747615625 grams. Dividing by 1,000 gives 0.141747615625 kilograms, and dividing 5 by 16 gives 0.3125 avoirdupois pounds. The screen rounds these values for readability while the workbook stores the canonical numbers.
Learn more. The NIST avoirdupois-ounce conversion table states that one ounce equals exactly 28.349523125 grams. For metric context, see the BIPM definition of the kilogram.
Why ounce type matters
The word “ounce” can refer to different mass standards. The international avoirdupois ounce is the everyday unit and equals one sixteenth of an avoirdupois pound. The troy ounce is heavier and is traditionally used for bullion and precious metals. For a value of 5, the difference is substantial: 5 avoirdupois ounces equal about 141.75 grams, while 5 troy ounces equal about 155.52 grams. Always use the unit printed on the source document rather than guessing from context.
NIST distinguishes mass from force in its guidance on SI units of mass. In everyday language people often say “weight,” but this converter performs a mass-unit conversion and does not account for local gravity.
Precision and practical interpretation
The constants used here are exact definitions, but a real measurement may have fewer reliable digits. A kitchen scale that reads to the nearest 0.1 ounce does not become more precise merely because the converted result shows several decimal places. Keep enough digits for your purpose, then round once at the end. For cooking, one or two decimal places in grams may be adequate; for calibrated technical work, retain the precision justified by the original instrument and method.