Weight converter (kg, lb, stone, oz)

Convert kg to lbs, pounds to kg, stone to kg and ounces to grams with the exact 1959 pound, plus tonnes, carats, troy ounces and tola.

Updated 27 September 2026Checked against 4 worked examples

Converted value

Shown to 12 significant figures, half-up

Conversion: 1 kg ≈ 2.204623 lb
Conversion factor: 2.20462262185
Exactness: Exact definitions, repeating decimal

1 kg is about 2.204623 lb.

The same amount counted in each unit

1 kg in every mass unit (15 rows)

Unit	Value	Definition
kilogram (kg)	1	Base unit
gram (g)	1,000	1 g = 0.001 kg, exact
milligram (mg)	1,000,000	1 mg = 0.000001 kg, exact
microgram (µg)	1,000,000,000	1 µg = 1 × 10⁻⁹ kg, exact
tonne (t)	0.001	1 t = 1,000 kg, exact
quintal (q)	0.01	1 q = 100 kg, exact
pound (lb)	2.204623	1 lb = 0.45359237 kg, exact
ounce (oz)	35.27396	1 oz = 0.028349523125 kg, exact
stone (st)	0.157473	1 st = 6.35029318 kg, exact
short ton (ton (US))	0.001102311	1 ton (US) = 907.18474 kg, exact
long ton (ton (UK))	0.0009842065	1 ton (UK) = 1,016.0469088 kg, exact
carat (ct)	5,000	1 ct = 0.0002 kg, exact
grain (gr)	15,432.36	1 gr = 0.00006479891 kg, exact
troy ounce (oz t)	32.15075	1 oz t = 0.0311034768 kg, exact
tola	85.73532	1 tola = 0.0116638038 kg, exact (180 grains (Indian standard))

How it's calculated S

Convert kilogram to pound
$1\ \text{kg} \div 0.45359237\ \tfrac{\text{kg}}{\text{lb}} = 2.20462262185\ \text{lb}$
1 lb = 0.45359237 kg, exact. Both units are defined exactly, but the converted value is a repeating decimal; it is shown to 12 significant figures.

About the weight converter

Every mass unit is a fixed number of kilograms. The pound has been exactly 0.45359237 kg since the 1959 international yard and pound agreement, so pounds, ounces (1/16 lb), stones (14 lb) and short and long tons all convert exactly. The kilogram itself has been defined since 2019 by a fixed value of the Planck constant.

The default converts 1 kg to 2.20462262185 lb, a repeating decimal shown to 12 significant figures. Body weight is the usual reason to convert: 70 kg is 154.32 lb, or just over 11 stone.

Weight here means mass, the sense in which scales and shops use the word. Precious metals use the troy ounce (31.1034768 g) rather than the ordinary ounce (28.349523125 g), and gems are weighed in metric carats of exactly 200 mg.

Worked examples

1 kg to pounds

Value: 1 kg
From: kilogram (kg)
To: pound (lb)

Converted value: 2.2046226218 lb
Exactness: Exact definitions, repeating decimal

Checked against: 1 lb = 0.45359237 kg exactly (1959 agreement); 1/0.45359237 = 100000000/45359237 (Python 3.8 fractions from the legal definitions)

1 stone in pounds

Value: 1 st
From: stone (st)
To: pound (lb)

Converted value: 14 lb

Checked against: NIST HB 44 App. C: 1 stone = 14 lb

1 ounce in grams

Value: 1 oz
From: ounce (oz)
To: gram (g)

Converted value: 28.349523125 g
Exactness: Exact

Checked against: 1/16 × 453.59237 g = 28.349523125 g (NIST HB 44 App. C)

1 tola in grams

Value: 1 tola
From: tola
To: gram (g)

Converted value: 11.6638038 g

Checked against: 1 tola = 180 grains; 1 grain = 64.79891 mg exactly (NIST HB 44 App. C): 180 × 64.79891 mg

Questions

How many pounds are in a kilogram?

2.20462262 lb. The pound is defined as exactly 0.45359237 kg, so 1 kg = 1 ÷ 0.45359237 = 2.2046226218… lb, a decimal that never ends. The shortcut “multiply by 2.2” is 0.2% low: 100 kg is 220.46 lb, not 220.

How many kilograms are in a stone?

Exactly 6.35029318 kg. A stone is 14 lb, and 14 × 0.45359237 kg gives that figure. Stones are still used for body weight in the UK and Ireland; 11 st 7 lb is 161 lb, which is 73.03 kg.

What is the difference between a troy ounce and an ounce?

A troy ounce is 31.1034768 g and an ordinary (avoirdupois) ounce is 28.349523125 g, so the troy ounce is 9.7% heavier. Gold, silver and platinum prices are quoted per troy ounce. A troy pound has 12 troy ounces, while the ordinary pound has 16 ounces.

Is a ton the same as a tonne?

No. A tonne (metric ton) is 1,000 kg. A US short ton is 2,000 lb, 907.18474 kg, and a UK long ton is 2,240 lb, 1,016.0469088 kg. The long ton is 12% heavier than the short ton, so shipping and freight documents should state which one they use.

How many grams is a tola?

11.6638038 g. A tola is 180 grains, and a grain is exactly 64.79891 mg (NIST Handbook 44), so 180 × 64.79891 mg = 11.6638038 g. Gold is still traded by the tola in South Asia and the Gulf, where a 10-tola bar weighs 116.64 g.

How accurate is the weight converter?

Accuracy depends on your inputs and the method's assumptions. Decimal arithmetic uses 50 significant digits, but estimates, numerical methods and source data can be less precise; the displayed rounding does not remove those limits. It is checked against 4 worked examples whose answers come from independent sources; for example, “1 kg to pounds” is checked against 1 lb = 0.45359237 kg exactly (1959 agreement); 1/0.45359237 = 100000000/45359237 (Python 3.8 fractions from the legal definitions).

Where does the method come from?

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

About this calculator

\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{kg} \end{gathered}

Sources

Checked against references

4 worked examples with independently sourced answers ship with this calculator. They run in the test suite; you can run them here too.