Gigagram To Kilogram Converter

1. Keep the mode on Gigagrams to kilograms, or switch to kg to Gg, or to Gg to Tg for million metric tons.
2. Enter the gigagrams from your table or report. Decimals such as 842.7 are fine.
3. Read the kilograms, then check the tonnes, kilotonnes, teragrams and short tons below.

A gigagram (symbol Gg) is a metric unit of mass equal to 10^9 grams, which is one million kilograms or 1,000 metric tonnes. It joins the SI prefix giga, meaning 10^9, to the gram.

The gigagram is the standard mass unit of greenhouse gas inventories. The 2006 IPCC Guidelines, Volume 1, Chapter 8, say emissions in summary and sectoral tables are generally expressed in gigagrams. Countries follow those guidelines when they report to the UNFCCC.

Giga was added to the SI in 1960, together with mega and tera, according to the NIST prefix history. The symbol is a capital G, and the gram symbol g stays lowercase, so the unit is written Gg.

Most readers know the same mass as the kilotonne. A tonne is 10^6 g, so 10^9 g / 10^6 g = 1,000 tonnes = 1 kt. Science tables prefer Gg because it stays inside the gram-based prefix system.

You multiply by 10^6, because giga is 10^9 g, kilo is 10^3 g, and 10^9 / 10^3 = 10^6.

1. Write the gigagrams, for example 842.7.
2. Move the decimal point 6 places to the right: 842.7 becomes 842,700,000.
3. Label it kg. To reach teragrams instead, move the decimal point 3 places left: 0.8427 Tg.

The step from kilograms to gigagrams and the step from gigagrams to teragrams are both powers of ten, so no rounding enters at any point.

An inventory line. A sector table lists 842.7 Gg of a gas. Multiply by 10^6 to get 842,700,000 kg. That is 842,700 t, or 0.8427 Tg.

A reporting threshold. UNFCCC reporting guidelines, quoted in the EPA inventory, use 500 kilotonnes of CO2 equivalent as a cap for calling a category insignificant. 500 kt is 500 Gg, or 5 x 10^8 kg.

A national total. EPA reports 2022 US gross emissions of 6,343 million metric tons of CO2 equivalent. In gigagrams that is 6,343,000 Gg, a seven-digit figure.

Reverse. A plant reports 2.75 x 10^8 kg. Divide by 10^6 to get 275 Gg, or 275 kt.

The 10^6 factor is fixed. Four things decide what your converted figure actually means.

Gas Mass or CO2 Equivalent

Inventories list each gas in its own mass and also as CO2 equivalent. 10 Gg of methane and 10 Gg CO2 eq. are different amounts of gas. The kilogram conversion is the same, but you must keep the label.

Reporting Precision

The IPCC chapter says a precision of 0.1 percent of the national total is adequate for each gas. For a total of 6,343,000 Gg, that is about 6,343 Gg, so extra decimals on a small line add nothing.

Capital G

Gg is giga. A lowercase g alone is the gram, so 5 g and 5 Gg differ by a factor of one billion.

Kilotonnes or Kilotons

A kilotonne is 1,000 metric tonnes. In US writing a kiloton can mean 1,000 short tons, which is about 907 t, so the two are not equal.

A gigagram and a kilotonne are identical. US short tons and UK long tons give different numbers for the same mass.

For pound figures, the kg to lbs converter takes the kilograms straight across. A UK ton figure goes through the long ton to kilogram converter.

Working with National Inventory Tables

Inventory tables built on the IPCC guidelines list gigagrams by gas and sector. Converting to kilograms lets you apply emission factors written per kilogram.

Matching Tables to Headline Totals

Summary tables use Gg, while press releases quote million metric tons. The Gg to Tg mode bridges the two in one step.

Scaling Down to a Facility or a Household

A single facility can report values in gigagrams, while a household footprint is counted in tonnes. The carbon footprint cost calculator covers the household side.

Each row is computed from 1 Gg = 10^6 kg = 1,000 t = 0.001 Tg.

To check the exponents by hand, the scientific notation calculator shows each step.

1. Multiplying by 10^9

10^9 is the number of grams in a gigagram. For kilograms, the factor is 10^6.

2. Treating Kilotons as Kilotonnes

A US kiloton of 2,000 lb tons is about 907 t, not 1,000 t.

3. Dropping the CO2 Eq. Label

Converting a CO2 equivalent figure to kg does not turn it into a mass of one real gas.

4. Dividing by 1,000 for Kilograms

Dividing by 1,000 turns gigagrams into teragrams, not kilograms. It moves the value the wrong way.

5. Writing GG or GG

Only Gg is correct. The prefix is uppercase and the gram symbol is lowercase.

The conversion is exact. Your result is only as good as the source figure and the label attached to it.

One gigagram is exactly 1,000,000 kg, which is 10^6 kg.

Yes. Both equal 1,000 metric tonnes, or 10^9 grams.

The 2006 IPCC Guidelines say summary and sectoral tables are generally expressed in Gg, and countries follow those guidelines when they report.

There are 1,000 Gg in 1 Tg, so 1 million metric tons is 1,000 Gg.

Half a gigagram is 500,000 kg, which is 500 tonnes.

There are 10^9 grams, one billion grams, in a gigagram.

One gigagram is about 1,102.31 short tons, because a short ton is 907.18474 kg.

Multiply by 10^6, the same as for Gg. For example, 120 kt CO2 eq is 1.2 x 10^8 kg CO2 eq.

No. Only Gg is correct: capital G for giga and lowercase g for gram.

No. The converter runs in your browser and nothing goes to our servers. Saved results stay in this browser only.

• Emissions in summary and sectoral tables are generally expressed in gigagram (Gg) (2006 IPCC Guidelines, Vol. 1, Chapter 8).
• US inventory Chapter 1, quoting the UNFCCC 500 kt CO2 eq insignificance cap and MMT reporting (US EPA, Inventory of US Greenhouse Gas Emissions and Sinks 1990-2022).
• SI prefixes table, giga G = 10^9 (BIPM, International Bureau of Weights and Measures).
• Metric SI prefixes, including when giga was added in 1960 (NIST Office of Weights and Measures).