Grams to Kilograms Converter (g to kg)

1. Leave the direction on Grams to kilograms, or pick kilograms to grams to reverse it.
2. Type the mass in grams, for example the weight printed on a food pack or shown on a kitchen scale.
3. Read the kilograms at once. The cards also show the factor, a kg plus g reading and the same mass in pounds.

The gram (g) and the kilogram (kg) are metric units of mass. The kilogram is the SI base unit of mass, and the gram is one thousandth of it. So 1 kg = 1,000 g.

The kilogram is unusual. It is the only SI base unit whose name already carries a prefix. That is why the prefixes for mass attach to the gram, as in milligram, rather than to the kilogram.

Since the 2018 revision of the SI, the kilogram is defined through a fixed value of the Planck constant, h = 6.62607015 x 10^-34 joule seconds. Before that, it was the mass of a metal cylinder kept near Paris, the International Prototype of the Kilogram. The change did not alter everyday conversions: 1,000 g is still 1 kg.

Mass and weight are different ideas. Mass is how much matter an object holds, and weight is the pull of gravity on it. In shops and kitchens people say weight, but a scale marked in grams or kilograms reports mass.

You divide grams by 1,000, because the SI prefix kilo stands for 10^3, which is 1,000.

1. Write the grams as a number, for example 750.
2. Move the decimal point 3 places to the left. Add zeros in front if you run out of digits: 750 becomes 0.750, and 5 becomes 0.005.
3. Write the unit as kg. Drop trailing zeros if you like: 0.750 kg and 0.75 kg are the same mass.

Baking. A recipe needs 1,250 g of flour. 1,250 / 1,000 = 1.25 kg. A 1 kg bag is not enough, since you need a quarter kilogram more.

Parcel. A package weighs 3,480 g on a postal scale. That is 3.48 kg, or 3 kg 480 g. Shipping price bands are usually set in kilograms, so the kilogram figure is what you compare.

Small amount. A spice jar holds 45 g. That is 0.045 kg. Here grams are the clearer unit, which is why small packs are labeled in grams.

Reverse. A bag of rice says 2.5 kg. 2.5 x 1,000 = 2,500 g. For a US reader that is about 5.51 lb. The kg to stone converter gives the UK body-weight form.

The factor never changes, so only three things can alter the number you write down.

Decimal Separator

Much of Europe writes a decimal comma, so 0,5 kg means 0.5 kg. A US reader could misread 1,500 g as 1.5 g. This page uses a point for decimals and commas for thousands.

Scale Resolution

A kitchen scale that reads to 1 g can only give kilograms to 3 decimals. Writing 0.4527 kg from that scale claims a precision it does not have.

Rounding

Three decimals in kilograms keep every whole gram. Rounding to 1 decimal, as in 1.3 kg for 1,250 g, can hide up to 50 g.

Net vs Gross Mass

A pack label gives the net mass of the contents. The mass you weigh at home includes the container, so the two differ.

Grams suit small amounts, kilograms suit anything you carry, and pounds are the US customary choice for both.

A US reader who knows a mass in pounds can work the other way with the lbs to kg converter, then read the grams from this page.

Scaling Recipes

Recipes written for a crowd list thousands of grams. Kilograms make it easy to see how many 1 kg bags to buy. The cooking measurement conversions guide covers cups and spoons.

Shipping and Luggage

Couriers and airlines outside the US quote limits in kilograms. Weigh items in grams, add them up, and convert once at the end.

School and Lab Work

Physics formulas expect SI base units, so masses must be in kilograms. A 250 g cart is 0.25 kg before you use it in force or energy sums.

Every value below is computed from 1 kg = 1,000 g, with pounds from 1 lb = 453.59237 g, rounded to 4 decimals.

1. Moving the Decimal the Wrong Way

Grams to kilograms makes the number smaller. If 500 g turns into 500,000, you multiplied instead of dividing.

2. Moving It Only 2 Places

Dividing by 100 gives 5 kg for 500 g, ten times too much. Kilo is 1,000, so move 3 places.

3. Writing KG or Kg

The SI symbol is a lowercase k: kg. Capital K is the kelvin, and capital G is the prefix giga.

4. Adding an S to the Symbol

Write 5 kg, not 5 kgs. SI symbols never take a plural s, and a space goes between the number and the symbol.

5. Mixing Up Gram and Grain

A grain is an old unit of about 0.0648 g, still seen for bullets and some medicines. It is not a gram.

The conversion is exact, so any error comes from the mass you measured or the rounding you chose.

There are exactly 1,000 grams in 1 kilogram. The prefix kilo means one thousand, so the factor is a definition, not a measurement.

Yes. 500 g is 0.5 kg, exactly half a kilogram. That is about 1.1 lb in US units.

Move the decimal point 3 places to the left. 2,340 g becomes 2.340 kg, and 60 g becomes 0.060 kg.

One hundred grams is 0.1 kg, one tenth of a kilogram. Many nutrition labels outside the US use 100 g as their reference amount.

Nearly. One kilogram is 2.20462 lb. Using 2.2 is about 0.2 percent low, which is fine for everyday use but not for trade.

The SI names the kilogram as its base unit of mass, a choice carried over from earlier metric standards. Because its name already holds a prefix, the other prefixes attach to the gram, as in milligram.

Write kg. SI symbols have no plural form, so 1 kg and 20 kg use the same symbol. The spelled-out word can be plural: 20 kilograms.

One million grams is 1,000 kg, which is 1 metric tonne. The tool flags values this large with the tonne figure.

No. The 2018 redefinition ties the kilogram to the Planck constant, but 1 kg is still exactly 1,000 g in every conversion.

No. The converter runs in your browser and nothing is sent to our servers. Anything you choose to Save stays in this browser only.

• SI units of mass: kilogram, gram, tonne, and mass vs weight (NIST Office of Weights and Measures).
• Metric SI prefixes, including kilo = 10^3 and symbol rules (NIST Office of Weights and Measures).
• The kilogram redefinition based on the Planck constant (NIST).
• SI base units and the 2018 revision (BIPM, International Bureau of Weights and Measures).
• Exact factor for the pound: 1 lb = 0.45359237 kg (NIST SP 811, Appendix B.8).