An ounce is 28.35 grams and a pound is 16 ounces, or 453.59 grams. A kilogram is 2.2046 pounds (1,000 grams, or 1,000,000 milligrams), and a US ton is 2,000 pounds, against 2,204.62 pounds for a metric ton. These are the avoirdupois units used for food, parcels and body weight; gold uses troy ounces.
Quick reference: weight conversion chart
| Unit | Grams | Ounces | Pounds | Kilograms |
|---|---|---|---|---|
| 1 milligram (mg) | 0.001 | 0.00003527 | 0.000002205 | 0.000001 |
| 1 gram (g) | 1 | 0.03527 | 0.002205 | 0.001 |
| 1 ounce (oz) | 28.34952 | 1 | 1/16 | 0.02835 |
| 1 troy ounce | 31.10348 | 1.097 | 0.0686 | 0.0311 |
| 1 pound (lb) | 453.59237 | 16 | 1 | 0.4536 |
| 1 kilogram (kg) | 1,000 | 35.274 | 2.2046 | 1 |
| 1 US short ton | 907,184.74 | 32,000 | 2,000 | 907.1847 |
| 1 long ton | 1,016,046.9088 | 35,840 | 2,240 | 1,016.0469 |
| 1 metric ton (tonne) | 1,000,000 | 35,273.962 | 2,204.6226 | 1,000 |
Values follow NIST SP 811 (Appendix B.8): the avoirdupois pound is exactly 0.45359237 kg and the troy ounce 31.1034768 g. Each section below covers one conversion in detail.
How many grams in an ounce?
One ounce is 28.35 grams. NIST lists the avoirdupois ounce as 28.34952 g, so ounces × 28.35 gives grams, and grams ÷ 28.35 gives ounces. For example, 4 oz is 113.4 g, and 100 g is 3.53 oz. This is the ounce used for food, mail and body weight; gold uses a heavier troy ounce.
The avoirdupois ounce is 1/16 of a pound, and NIST's conversion factors (SP 811, Appendix B.8) give it as 28.34952 grams, or 0.02834952 kg. US nutrition labels use a rounded 28 g instead, as explained under label ounces.
Formulas: grams in an ounce
grams = ounces × 28.35
ounces = grams ÷ 28.35
The factor 28.35 is accurate to about 0.01%. For mental math, 30 is easy but runs 5.8% high, so 3 oz as "90 g" is really 85 g.
Ounces to grams chart
| Ounces | Grams |
|---|---|
| 1/4 oz | 7.09 |
| 1/2 oz | 14.17 |
| 1 oz | 28.35 |
| 2 oz | 56.70 |
| 3 oz | 85.05 |
| 4 oz (1/4 lb) | 113.40 |
| 6 oz | 170.10 |
| 8 oz (1/2 lb) | 226.80 |
| 12 oz (3/4 lb) | 340.19 |
| 16 oz (1 lb) | 453.59 |
The converters oz to grams and grams to ounces take any value; pounds to grams and oz to kg cover the bigger steps.
Grams to ounces chart
| Grams | Ounces |
|---|---|
| 10 g | 0.35 |
| 25 g | 0.88 |
| 50 g | 1.76 |
| 100 g | 3.53 |
| 150 g | 5.29 |
| 200 g | 7.05 |
| 250 g | 8.82 |
| 500 g | 17.64 |
| 1,000 g (1 kg) | 35.27 |
Worked examples: grams in an ounce
Example 1: a recipe in grams
A recipe calls for 250 g of butter. 250 ÷ 28.34952 = 8.82 oz, a little under half a pound (8 oz = 226.8 g).
Example 2: a recipe in ounces
A recipe asks for 6 oz of chocolate. 6 × 28.34952 = 170.1 g. Using the label figure of 28 g per ounce would give 168 g, a gap of 2.1 g.
Example 3: portions from a bag
A 500 g bag of pasta split into 2 oz portions: 2 oz = 56.7 g, and 500 ÷ 56.7 = 8.8 portions, so 8 full portions with 46.4 g left (500 − 8 × 56.7).
Example 4: label serving to grams
A serving size listed as 3 oz weighs 3 × 28.35 = 85.05 g by the exact factor. Under the FDA rounding of 28 g per ounce, the same 3 oz is stated as 84 g.
Example 5: a pound in grams
A pound is 16 × 28.34952 = 453.59 g. So 2 lb is 907.18 g, and 1 kg is 35.27 oz or 2.205 lb. The kg to lbs converter does the larger conversions.
Quick ways to remember: grams in an ounce
- 1 oz is about 28 g and 1 lb is about 454 g.
- A quarter pound is 4 oz, about 113 g.
- Round to 28 only for rough work: for baking, use 28.35 or a scale that switches units. The metric vs imperial guide explains how the two systems relate.
How many grams in a pound?
One pound is 453.59 grams. NIST lists the avoirdupois pound as 0.4535924 kg, so pounds × 453.59 gives grams, and grams ÷ 453.59 gives pounds. For example, 2 lb is 907.18 g and 500 g is 1.10 lb. Half a pound is 226.8 g and a quarter pound is 113.4 g.
The pound is defined in metric terms: NIST's conversion table (SP 811, Appendix B.8) gives 1 lb = 0.4535924 kg, or 453.5924 g. The gram is 1/1,000 of a kilogram. A pound is also 16 ounces, which is why 453.59 ÷ 16 = 28.35 g per ounce, the figure in how many grams in an ounce.
Formulas: grams in a pound
grams = pounds × 453.59
pounds = grams ÷ 453.59
kilograms = pounds × 0.4536
pounds = kilograms × 2.2046
The converters pounds to grams and grams to pounds take any value, and the kg to lbs calculator covers kilograms.
Pounds to grams chart
| Pounds | Grams |
|---|---|
| 1/4 lb (4 oz) | 113.4 |
| 1/2 lb (8 oz) | 226.8 |
| 3/4 lb (12 oz) | 340.2 |
| 1 lb | 453.6 |
| 2 lb | 907.2 |
| 5 lb | 2,268.0 |
| 10 lb | 4,535.9 |
| 25 lb | 11,339.8 |
| 50 lb | 22,679.6 |
| 100 lb | 45,359.2 |
Grams to pounds chart
| Grams | Pounds | Pounds and ounces |
|---|---|---|
| 100 g | 0.220 | 3.53 oz |
| 200 g | 0.441 | 7.05 oz |
| 250 g | 0.551 | 8.82 oz |
| 500 g | 1.102 | 1 lb 1.64 oz |
| 750 g | 1.653 | 1 lb 10.46 oz |
| 1,000 g | 2.205 | 2 lb 3.27 oz |
| 2,000 g | 4.409 | 4 lb 6.55 oz |
Worked examples: grams in a pound
Example 1: a recipe from pounds to grams
A recipe calls for 1.5 lb of potatoes. 1.5 × 453.59237 = 680.4 g. A 750 g bag from a metric store is 750 ÷ 453.59237 = 1.65 lb, so it covers the recipe with 69.6 g to spare.
Example 2: how much is a kilogram?
A 1 kg bag of flour is 1,000 ÷ 453.59237 = 2.205 lb, which is 2 lb plus 0.2046 × 16 = 3.27 oz. Two pounds of flour is 907 g, about 93 g short of a kilogram.
Example 3: body weight
A person weighing 150 lb has a mass of 150 × 0.45359237 = 68.04 kg. A weight of 80 kg is 80 × 2.2046226 = 176.4 lb. The kg to lbs calculator does this in either direction.
Example 4: how much does rounding matter?
Using 454 g per pound gives 100.09% of the true value, an error of 0.09%. Using 450 g gives 99.2% (0.8% low), so 10 lb comes out as 4,500 g instead of 4,535.9 g, a 35.9 g shortfall. Rounding to 450 is fine for rough work, not for baking or postal weights.
Example 5: a weight against a nutrition label
US nutrition labels state that 1 oz in weight means 28 g (21 CFR 101.9(b)(5)(viii)). A pound would be 16 × 28 = 448 g on that rule, 5.6 g lower than the true 453.6 g. Labels round for readability; a scale does not.
Why does the pound have two gram figures online?
Some pages say 453.59 g and some say 454 g. The first is the NIST-based value and the second is a rounded one. Neither is wrong for everyday use, but the rounded value is 0.4 g high. The metric figure 453.59 g is for the everyday (avoirdupois) pound; precious metals use troy weights, covered under troy ounce and troy, label and fluid ounces.
Quick ways to remember: grams in a pound
- 1 lb is about 454 g, and 1 kg is about 2.2 lb.
- A half pound is about 227 g and a quarter pound about 113 g.
- Divide kilograms by 0.4536 or multiply by 2.2 for a quick pound estimate.
- For the cup side, see cups to grams; the metric vs imperial guide puts the systems side by side.
How many ounces in a pound?
There are 16 ounces in 1 pound. To convert pounds to ounces, multiply by 16; to convert ounces to pounds, divide by 16. Half a pound is 8 ounces, a quarter pound is 4 ounces, and 2.5 pounds is 40 ounces. This applies to the avoirdupois pound and ounce used for groceries, parcels and body weight in the US.
NIST's conversion factors (SP 811, Appendix B.8) list the avoirdupois pound as 0.4535924 kg and the avoirdupois ounce as 0.02834952 kg. Dividing, 0.4535924 ÷ 0.02834952 = 16.000, so a pound always contains 16 of the ounces used on a kitchen scale.
In grams, one pound is about 453.59 g (16 × 28.34952), and one ounce is about 28.35 g.
Ounces to pounds chart
| Pounds | Ounces | Grams (approx.) | Kilograms (approx.) |
|---|---|---|---|
| 1/4 lb | 4 | 113.4 | 0.113 |
| 1/2 lb | 8 | 226.8 | 0.227 |
| 3/4 lb | 12 | 340.2 | 0.340 |
| 1 lb | 16 | 453.6 | 0.454 |
| 1 1/2 lb | 24 | 680.4 | 0.680 |
| 2 lb | 32 | 907.2 | 0.907 |
| 2.2 lb | 35.2 | 997.9 | 0.998 |
| 5 lb | 80 | 2,267.96 | 2.268 |
| 10 lb | 160 | 4,535.9 | 4.536 |
The converters lbs to oz and oz to lbs handle any other value, and pounds to grams goes straight to the metric side.
How do I convert ounces to pounds and ounces?
Divide the ounces by 16. The whole number is the pounds, and 16 times the remainder is the ounces left over.
| Total ounces | Calculation | Result |
|---|---|---|
| 20 oz | 20 ÷ 16 = 1 remainder 4 | 1 lb 4 oz |
| 52 oz | 52 ÷ 16 = 3 remainder 4 | 3 lb 4 oz |
| 118 oz | 118 ÷ 16 = 7 remainder 6 | 7 lb 6 oz |
| 100 oz | 100 ÷ 16 = 6 remainder 4 | 6 lb 4 oz |
Worked examples: ounces in a pound
Example 1: price per pound
Ground meat costs $4.99 per pound and the package weighs 12 oz. 12 ÷ 16 = 0.75 lb, and 4.99 × 0.75 = $3.74.
Example 2: pounds and ounces to ounces
A weight of 7 lb 6 oz is 7 × 16 + 6 = 118 oz. In kilograms, 118 × 0.02834952 = 3.345 kg.
Example 3: a weight limit in ounces
A scale reads in ounces and a rule allows up to 1 lb. A package of 0.75 lb is 0.75 × 16 = 12 oz, so it is 4 oz under the limit.
Example 4: splitting a bulk bag
A 5 lb bag of flour split into 6 oz portions gives 80 ÷ 6 = 13.33, so 13 full portions with 2 oz left over (80 − 78).
Example 5: ounces to grams for a metric recipe
A recipe lists 8 oz of cream cheese. 8 × 28.34952 = 226.8 g, about half a pound. The label rounding of 28 g per ounce would give 224 g.
Quick ways to remember: ounces in a pound
- 16 ounces = 1 pound, and 8, 4 and 12 are the half, quarter and three-quarter pound.
- Multiply a pound weight by 16 to move to ounces, divide by 16 to move back.
- About 28 g per ounce, about 454 g per pound is accurate enough for most cooking; the metric vs imperial guide compares the two systems in more depth, and kg to lbs converts larger weights.
How many pounds in a kilogram?
One kilogram is 2.2046 pounds. NIST lists the avoirdupois pound as 0.4535924 kg (defined as exactly 0.45359237 kg), so pounds = kilograms ÷ 0.45359237, or kilograms × 2.20462. For example, 5 kg is 11.02 lb and 70 kg is 154.32 lb. One kilogram also equals 35.274 ounces.
The kilogram is the SI base unit of mass; the pound is a US customary unit of 16 avoirdupois ounces. Using NIST's factor, 1 ÷ 0.45359237 = 2.204623 pounds per kilogram. Multiplying by 16 gives 35.274 ounces per kilogram.
Formulas: pounds in a kilogram
pounds = kilograms × 2.20462
kilograms = pounds × 0.45359237 (or pounds ÷ 2.20462)
ounces = kilograms × 35.274
grams = pounds × 453.59237
Converters: kg to lbs, kg to oz, pounds to grams and kg to stone.
Kilograms to pounds chart
| Kilograms | Pounds |
|---|---|
| 1 | 2.20 |
| 2 | 4.41 |
| 5 | 11.02 |
| 10 | 22.05 |
| 25 | 55.12 |
| 50 | 110.23 |
| 70 | 154.32 |
| 100 | 220.46 |
Pounds to kilograms chart
| Pounds | Kilograms |
|---|---|
| 1 | 0.454 |
| 2 | 0.907 |
| 5 | 2.268 |
| 10 | 4.536 |
| 20 | 9.072 |
| 50 | 22.680 |
| 100 | 45.359 |
| 150 | 68.039 |
| 200 | 90.718 |
Worked examples: pounds in a kilogram
Example 1: body weight
A person weighing 154 lb has a mass of 154 × 0.45359237 = 69.85 kg, and 180 lb is 81.65 kg. Weight-based formulas such as the BMR calculator work in kilograms, so pounds must be converted first.
Example 2: luggage
An airline limit of 23 kg is 23 × 2.20462 = 50.7 lb. A bag that weighs 50 lb is 22.68 kg, so it fits under the limit by 0.32 kg.
Example 3: a recipe
A recipe calling for 1.5 kg of potatoes needs 1.5 × 2.20462 = 3.31 lb, or 52.9 oz.
Example 4: a baby's weight
A newborn weighing 7 lb 8 oz is 7.5 lb, which is 7.5 × 0.45359237 = 3.40 kg.
Example 5: the stone
A stone is 14 pounds (6.35 kg). A weight of 70 kg is 154.32 lb, which is 11 stone and 0.32 lb.
Quick ways to estimate: pounds in a kilogram
- Kilograms to pounds: double it, then add 10% (70 kg: 140 + 14 = 154 lb, against the exact 154.32).
- Pounds to kilograms: halve it, then subtract 10% (150 lb: 75 - 7.5 = 67.5 kg, against 68.04).
- Check: a kilogram is always a little more than 2 pounds (2.2).
A kilogram and a pound measure mass, but scales and food labels often show only one of them; see the metric vs imperial guide for related conversions.
How many pounds in a ton?
A US ton, also called a short ton, is 2,000 pounds. Two other tons exist: the long ton of 2,240 pounds and the metric ton (tonne) of 1,000 kilograms, which is 2,204.62 pounds. To convert pounds to US tons, divide by 2,000; 15,000 lb is 7.5 short tons, and 4,000 lb is exactly 2 tons.
NIST's conversion table (SP 811, Appendix B.8) lists the short ton as 2,000 lb and the long ton as 2,240 lb. The metric ton, written t and called a tonne outside the US, is exactly 1,000 kg. Using the pound as 0.45359237 kg:
| Ton | Pounds | Kilograms |
|---|---|---|
| Short ton (US) | 2,000 | 907.18 |
| Long ton (UK) | 2,240 | 1,016.05 |
| Metric ton (tonne) | 2,204.62 | 1,000 |
A long ton is 12% heavier than a short ton (2,240 ÷ 2,000 = 1.12), and a metric ton is about 10.2% heavier (2,204.62 ÷ 2,000 = 1.1023).
Formulas: pounds in a ton
US tons = pounds ÷ 2,000
pounds = US tons × 2,000
metric tons = pounds × 0.00045359237
pounds = metric tons × 2,204.62
long tons = pounds ÷ 2,240
Converters: tons to pounds, pounds to tons and kg to lbs.
Tons to pounds chart
| Tons | US pounds | Metric tons in pounds |
|---|---|---|
| 1/4 | 500 | 551.2 |
| 1/2 | 1,000 | 1,102.3 |
| 1 | 2,000 | 2,204.6 |
| 1.5 | 3,000 | 3,306.9 |
| 2 | 4,000 | 4,409.2 |
| 5 | 10,000 | 11,023.1 |
| 10 | 20,000 | 22,046.2 |
Pounds to tons chart
| Pounds | Short tons | Metric tons |
|---|---|---|
| 500 | 0.25 | 0.227 |
| 1,000 | 0.5 | 0.454 |
| 4,000 | 2 | 1.814 |
| 6,000 | 3 | 2.722 |
| 15,000 | 7.5 | 6.804 |
Worked examples: pounds in a ton
Example 1: a pickup truck payload
A payload rating of 1,500 lb is 1,500 ÷ 2,000 = 0.75 ton in the US sense. The same load is 680.4 kg (1,500 × 0.45359237).
Example 2: a delivery of gravel
A load of 7,000 lb is 7,000 ÷ 2,000 = 3.5 US tons. If the supplier meant metric tons, the same weight is 3.18 t, so a quote per ton needs the type.
Example 3: a shipping weight in metric tons
A container carrying 24 metric tons weighs 24 × 2,204.62 = 52,911 lb, which is 26.46 short tons.
Example 4: a long ton
A weight of 6,720 lb is 6,720 ÷ 2,240 = 3 long tons, or 3.36 short tons (6,720 ÷ 2,000), or 3.05 metric tons.
Example 5: ounces
One short ton holds 2,000 × 16 = 32,000 oz (see how many ounces in a pound).
Which ton is meant?
- US contexts (trucks, scrap, coal, gravel, freight quotes) mean the short ton, 2,000 lb.
- Metric contexts mean 1,000 kg. NIST notes that the metric ton is called a "tonne" outside the US, and using that word avoids confusion.
- The long ton is mostly historical and appears in older UK usage.
- Three tons is 6,000 lb as US short tons, 6,613.9 lb as metric tons and 6,720 lb as long tons.
Quick ways to estimate: pounds in a ton
- Pounds to US tons: halve the number and drop three zeros (15,000 lb: 7,500 → 7.5 tons).
- Metric tons to pounds: multiply by 2,200 (5 t ≈ 11,000 lb, exact 11,023).
- Check: a metric ton is always about 10% more than a US ton.
How many milligrams in a gram?
There are 1,000 milligrams in a gram. The prefix milli means one thousandth, so 1 mg = 0.001 g. Multiply grams by 1,000 to get milligrams, and divide milligrams by 1,000 to get grams: 2.5 g is 2,500 mg, and 350 mg is 0.35 g. A kilogram holds 1,000,000 mg.
The International System of Units builds larger and smaller units from a base unit by adding a prefix. NIST's prefix list gives milli (m) as 10^-3, kilo (k) as 10^3 and micro (μ) as 10^-6. The gram is 1/1,000 of the base unit, the kilogram, so one gram is 1,000 mg, and a milligram is a thousandth of a gram.
NIST adds a detail for mass: because the kilogram already carries the prefix kilo, its multiples and submultiples are formed from the gram, so the correct form is 1 mg, not 1 μkg.
Formulas: milligrams in a gram
milligrams = grams × 1,000
grams = milligrams ÷ 1,000
grams = kilograms × 1,000
micrograms = milligrams × 1,000
The converters grams to mg, grams to kg and mg to mcg take any value.
Metric prefix chart
| Prefix | Symbol | Factor | Mass example | Length example | Volume example |
|---|---|---|---|---|---|
| kilo | k | 1,000 | 1 kg = 1,000 g | 1 km = 1,000 m | 1 kL = 1,000 L |
| (base) | 1 | 1 g | 1 m | 1 L | |
| deci | d | 0.1 | 1 dg = 0.1 g | 1 dm = 0.1 m | 1 dL = 0.1 L |
| centi | c | 0.01 | 1 cg = 0.01 g | 1 cm = 0.01 m | 1 cL = 0.01 L |
| milli | m | 0.001 | 1 mg = 0.001 g | 1 mm = 0.001 m | 1 mL = 0.001 L |
| micro | μ | 0.000001 | 1 μg = 0.000001 g | 1 μm = 0.000001 m | 1 μL = 0.000001 L |
Moving one step between kilo, base and milli multiplies or divides by 1,000, while centi is a factor of 100. That gives 1 m = 100 cm = 1,000 mm, and 1 cm = 10 mm. See the converters cm to mm, liters to ml and ml to liters.
Grams to milligrams chart
| Grams | Milligrams |
|---|---|
| 0.001 g | 1 mg |
| 0.01 g | 10 mg |
| 0.1 g | 100 mg |
| 0.25 g | 250 mg |
| 0.5 g | 500 mg |
| 1 g | 1,000 mg |
| 2 g | 2,000 mg |
| 5 g | 5,000 mg |
| 10 g | 10,000 mg |
| 100 g | 100,000 mg |
| 1 kg (1,000 g) | 1,000,000 mg |
Worked examples: milligrams in a gram
Example 1: a food label
A label lists 480 mg of sodium per serving. 480 ÷ 1,000 = 0.48 g per serving, so 5 servings contain 5 × 480 = 2,400 mg, or 2.4 g.
Example 2: a supplement with grams on the bottle
A 1.5 g powder serving is 1.5 × 1,000 = 1,500 mg. A 250 mg capsule would take 6 capsules to reach the same amount (1,500 ÷ 250 = 6).
Example 3: milligrams to micrograms
A vitamin listed at 0.5 mg is 0.5 × 1,000 = 500 μg. Reading "500 mcg" as 500 mg would be an error by a factor of 1,000.
Example 4: the same idea for volume
A 750 mL bottle is 750 ÷ 1,000 = 0.75 L. A 2.5 L bottle is 2,500 mL. The rule is identical because milli is milli: it always means a thousandth.
Example 5: the same idea for length
A 2.4 m board is 2.4 × 100 = 240 cm or 2.4 × 1,000 = 2,400 mm. A 35 mm screw is 3.5 cm and 0.035 m. To mix in imperial, 25.4 mm is 1 inch; see mm to inches.
Common mistakes: milligrams in a gram
- Mixing mg and mcg. One milligram is 1,000 micrograms, and mcg or μg is the smaller unit. Check the symbol before comparing amounts.
- Treating g as kg. 1 kg is 1,000 g, not 100 g. The factor of 1,000 applies to kilo, milli and base units; only centi (a hundredth) uses 100.
- Confusing mass and volume. A milliliter is a volume and a milligram is a mass. Water is close to 1 g per mL, but many liquids are not; the cups to grams guide shows why.
- Mixing systems. For ounces and pounds see how many grams in a pound and the metric vs imperial guide.
This page explains unit conversion for general reference; it is educational and not medical or dosing advice.
Troy, label and fluid ounces
Every figure above uses the avoirdupois ounce of 28.34952 g, the ounce used for food, mail and body weight. Three other "ounces" are easy to confuse with it.
What is a troy ounce in grams?
Gold, silver and platinum are quoted in troy ounces. NIST lists the troy ounce as 31.10348 g, against 28.34952 g for the avoirdupois ounce. The ratio is 31.10348 ÷ 28.34952 = 1.097, so a troy ounce is about 9.7% heavier. A 1 troy ounce coin weighs 31.10 g, not 28.35 g, and treating them as the same would be a 2.75 g error per ounce. A pound of flour and a "pound" of a precious metal are therefore not counted in the same ounces. Kitchen scales and parcel scales use the avoirdupois ounce.
Why do food labels say 28 g per ounce?
For US nutrition labels, 21 CFR 101.9(b)(5)(viii) states that 1 oz in weight means 28 g. The label value is about 1.2% lower than the exact one (28 ÷ 28.34952 = 0.988), which is why a "1 oz (28 g)" serving is not exactly one ounce and label figures built on that rule run about 1.2% low. A pound would be 16 × 28 = 448 g on that rule, 5.6 g lower than the true 453.6 g. Labels round for readability; a scale does not.
Can fluid ounces be converted to grams?
Not directly. A fluid ounce is a unit of volume, 29.57353 mL for the US unit (16 US fl oz make a pint), while grams and the pound's 16 ounces are units of weight. The conversion needs the density: water at about 1 g/mL gives roughly 29.6 g per fluid ounce, and a US pint of water weighs a little over a pound, but oil, honey and flour weigh differently per fluid ounce. That is why a recipe in cups cannot be turned into ounces of weight without the ingredient's density; see how many ounces in a cup and the cups to grams chart, which lists ingredients one by one.