A gram is a metric unit of mass equal to one thousandth of a kilogram. It is common in food labels, recipes, nutrition, lab work, medicine, postal weight, jewelry, and small product specifications.
Quick facts
- Unit name
- gram
- Plural
- grams
- Symbol
- g
- Quantity
- mass
- System
- metric system
- Kilogram relation
- 1 g = 0.001 kg
- Milligram relation
- 1 g = 1,000 mg
- Ounce relation
- 1 oz = 28.349523125 g
Visual scale
One gram is small, but large enough for kitchen scales, nutrition labels, and small product weights.
Definition and exact value
The gram is a decimal metric mass unit. One gram is exactly one thousandth of a kilogram, and one kilogram equals exactly 1,000 grams.
Symbol and writing rules
The standard symbol for gram is g. Unit symbols are not pluralized, so write 1 g and 12 g, not 12 gs. In technical writing, put a space between the number and the symbol.
How heavy is one gram?
One gram is useful for small quantities. It is much smaller than a kilogram, larger than a milligram, and close to the scale used for food portions, ingredients, small packages, and laboratory samples.
Food scale
Nutrition labels and recipes often use grams for carbohydrates, protein, fat, sugar, flour, coffee, and spices.
Product scale
Small electronics, jewelry, cosmetics, and parcels may be weighed in grams.
Science scale
Laboratory balances commonly report grams or milligrams depending on precision.
Gram in the metric hierarchy
The gram sits between the milligram and kilogram. It is small enough for everyday portions but large enough to avoid long milligram values for many normal objects.
| Unit | Symbol | Relationship to gram | Typical use |
|---|---|---|---|
| milligram | mg | 1 mg = 0.001 g | medicine, chemistry, supplements |
| gram | g | 1 g | food, small goods, lab work |
| kilogram | kg | 1 kg = 1,000 g | body weight, shipping, groceries |
| metric ton | t | 1 t = 1,000,000 g | bulk materials, freight, industry |
Gram vs kilogram
The gram and kilogram are both metric mass units. Use grams for smaller values and kilograms for larger everyday weights. One kilogram equals exactly 1,000 grams.
Gram vs ounce
The gram is metric; the ounce is customary and imperial. One ounce equals exactly 28.349523125 grams, so gram-to-ounce conversion often produces decimal results.
Visual comparison
Common uses
- Food labels, nutrition facts, recipes, coffee, baking, and ingredient portions.
- Small parcels, postal weights, consumer products, cosmetics, and electronics.
- Laboratory measurements, chemistry, samples, and classroom science.
- Jewelry, precious metals, supplements, and medical dosage contexts when appropriate.
How grams are measured
Grams are measured with scales or balances. Kitchen scales are useful for food and recipes; postal scales for packages; laboratory balances for samples that need higher precision.
- Choose a scale with enough sensitivity for the object.
- Tare the container before adding the item or ingredient.
- Record decimal grams only when the scale precision supports them.
Precision and rounding
For recipes and food portions, whole grams are often enough. For medicine, supplements, chemistry, or jewelry, smaller units such as milligrams or decimal grams may be required. Always match the unit to the precision of the measurement.
Conversion formulas
Gram conversion table
| Grams | Kilograms | Milligrams | Ounces | Pounds |
|---|---|---|---|---|
| 1 g | 0.001 kg | 1,000 mg | 0.03527396195 oz | 0.0022046226 lb |
| 10 g | 0.01 kg | 10,000 mg | 0.3527396195 oz | 0.0220462262 lb |
| 28.349523125 g | 0.028349523125 kg | 28,349.523125 mg | 1 oz | 0.0625 lb |
| 100 g | 0.1 kg | 100,000 mg | 3.527396195 oz | 0.2204622622 lb |
| 1,000 g | 1 kg | 1,000,000 mg | 35.27396195 oz | 2.204622622 lb |
Common mistakes
- Confusing grams and kilograms: 1 kg equals 1,000 g.
- Confusing grams and milligrams: 1 g equals 1,000 mg, which matters in medicine and supplements.
- Using ounce and fluid ounce interchangeably: ounces measure weight or mass, while fluid ounces measure volume.
- Rounding grams to ounces too early: keep extra decimal places for recipes, labels, and product specifications.
- Pluralizing the symbol: write 12 g, not 12 gs.
Related Xunits pages
Gram converters
Weight references
FAQ
How many grams are in one kilogram?
One kilogram equals exactly 1,000 grams.
How many ounces are in one gram?
One gram equals about 0.03527396195 ounces.
How many grams are in one ounce?
One ounce equals exactly 28.349523125 grams.
What is the symbol for gram?
The standard symbol is g.
Is gram an SI base unit?
No. The SI base unit for mass is the kilogram. The gram is a decimal metric unit equal to one thousandth of a kilogram.
Should I use grams or milligrams?
Use grams for food, small goods, and everyday quantities. Use milligrams when the quantity is very small or when medicine, supplements, or lab work require more precision.
Is gram weight or mass?
Gram is a mass unit. In everyday language, it is often used for weight labels and scale readings.
Reference notes
This guide uses exact metric relationships for grams, kilograms, and milligrams, plus the exact ounce relationship of 1 oz = 28.349523125 g.