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Tonnes to kilograms

Multiply tonnes by 1,000 to get kilograms.

1 t = 1,000 kgBIPM SI
t
10,000kg

10 t = 10,000 kg

How to convert tonnes to kilograms

The kilogram is the SI base unit of mass, fixed since 2019 by defining the Planck constant as exactly 6.62607015×10⁻³⁴ J·s. The tonne is exactly 1000 kilograms — the metric ton.

Worked example — 10 t: 10 × 1,000 = 10,000 kg.

Tonnes to kilograms table

Common conversions. The reverse table is on kilograms to tonnes.
TonnesKilograms
0.5 t500 kg
1 t1,000 kg
2 t2,000 kg
5 t5,000 kg
10 t10,000 kg
25 t25,000 kg
50 t50,000 kg
100 t100,000 kg
1,000 t1,000,000 kg

Reverse and related

About tonnes and kilograms

Tonne (t)

1 t = 1,000 kg

Definition. Exactly 1000 kilograms — the metric ton

History and origin

The tonne, or metric ton, was defined as exactly 1000 kilograms as the metric system spread, giving a convenient unit for heavy loads. It is accepted for use with the SI.

Current use

Tonnes measure bulk and freight weight, vehicle mass and industrial quantities throughout the metric world.

Source: BIPM, The International System of Units (SI), 9th ed. (2019)

Kilogram (kg)

1 kg = 0.001 t

Definition. The SI base unit of mass, fixed since 2019 by defining the Planck constant as exactly 6.62607015×10⁻³⁴ J·s

History and origin

The kilogram began in 1795 as the mass of one litre of water at the melting point of ice, and from 1889 was embodied in a platinum-iridium cylinder kept near Paris, the International Prototype Kilogram. In 2019 the SI retired that physical artefact and redefined the unit through a fixed value of the Planck constant, leaving its size unchanged.

Current use

It is the base unit of mass almost everywhere on Earth. The main everyday exception is the United States, where people weigh in pounds even though US science, medicine and industry work in kilograms.

Source: BIPM, The International System of Units (SI), 9th ed. (2019)

Where people use this

Tonnes: bulk and freight weight, vehicles. Kilograms: body weight outside the US, groceries and produce, checked-luggage limits. 1 tonne is exactly 1000 kg.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
1 kg = 0.001 t, so 1 t = 1 ÷ 0.001 = 1,000 kg.

Every value is carried to full double precision; the display is rounded.

Both units are defined in BIPM, The International System of Units (SI), 9th ed. (2019).

Questions people ask

How many kg in a tonne?

One tonne is exactly 1000 kilograms.

How many kg is 2 tonnes?

2 tonnes is 2000 kg.

How many kg is half a tonne?

Half a tonne is 500 kg.

All tonne conversions