The following are examples of orders of magnitude for different lengths.

Overview

Detailed list

To help compare different orders of magnitude, the following list describes various lengths between metres and metres.

Subatomic scale

Atomic to cellular scale

Cellular to human scale

Human to astronomical scale

Astronomical scale

1 quectometre and less

The quectometre (SI symbol: qm) is a unit of length in the metric system equal to 10−30 metres. To help compare different orders of magnitude, this section lists lengths shorter than 10−30 m (1 qm).

1 rontometre

The rontometre (SI symbol: rm) is a unit of length in the metric system equal to 10−27 metres.

10 rontometres

1 yoctometre

The yoctometre (SI symbol: ym) is a unit of length in the metric system equal to 10−24 metres.

1 zeptometre

The zeptometre (SI symbol: zm) is a unit of length in the metric system equal to 10−21 metres. To help compare different orders of magnitude, this section lists lengths between 10−21 m and 10−20 m (1 zm and 10 zm).

10 zeptometres

To help compare different orders of magnitude, this section lists lengths between 10−20 m and 10−19 m (10 zm and 100 zm).

100 zeptometres

To help compare different orders of magnitude, this section lists lengths between 10−19 m and 10−18 m (100 zm and 1 am).

1 attometre

The attometre (SI symbol: am) is a unit of length in the metric system equal to 10−18 metres. To help compare different orders of magnitude, this section lists lengths between 10−18 m and 10−17 m (1 am and 10 am).

10 attometres

To help compare different orders of magnitude, this section lists lengths between 10−17 m and 10−16 m (10 am and 100 am).

100 attometres

To help compare different orders of magnitude, this section lists lengths between 10−16 m and 10−15 m (100 am and 1 fm).

1 femtometre (or 1 fermi)

The femtometre (SI symbol: fm) is a unit of length in the metric system equal to 10−15 metres. In particle physics, this unit is sometimes called a fermi, also with abbreviation "fm". To help compare different orders of magnitude, this section lists lengths between 10−15 metres and 10−14 metres (1 femtometre and 10 fm).

10 femtometres

To help compare different orders of magnitude, this section lists lengths between 10−14 m and 10−13 m (10 fm and 100 fm).

100 femtometres

To help compare different orders of magnitude, this section lists lengths between 10−13 m and 10−12 m (100 fm and 1 pm).

1 picometre

The picometre (SI symbol: pm) is a unit of length in the metric system equal to 10−12 metres (1⁄1 000 000 000 000 m = 0.000 000 000 001 m). To help compare different orders of magnitude this section lists lengths between 10−12 and 10−11 m (1 pm and 10 pm).

10 picometres

To help compare different orders of magnitude this section lists lengths between 10−11 and 10−10 m (10 pm and 100 pm).

100 picometres

To help compare different orders of magnitude this section lists lengths between 10−10 and 10−9 m (100 pm and 1 nm; 1 Å and 10 Å).

1 nanometre

The nanometre (SI symbol: nm) is a unit of length in the metric system equal to 10−9 metres (1⁄1 000 000 000 m = 0.000 000 001 m). To help compare different orders of magnitude, this section lists lengths between 10−9 and 10−8 m (1 nm and 10 nm).

10 nanometres

To help compare different orders of magnitude this section lists lengths between 10−8 and 10−7 m (10 nm and 100 nm).

100 nanometres

To help compare different orders of magnitude, this section lists lengths between 10−7 and 10−6 m (100 nm and 1 μm).

1 micrometre (or 1 micron)

The micrometre (SI symbol: μm) is a unit of length in the metric system equal to 10−6 metres (1⁄1 000 000 m = 0.000 001 m). To help compare different orders of magnitude, this section lists some items with lengths between 10−6 and 10−5 m (between 1 and 10 micrometres, or μm).

10 micrometres

To help compare different orders of magnitude, this section lists lengths between 10−5 m and 10−4 m (10 μm and 100 μm).

100 micrometres

To help compare different orders of magnitude, this section lists lengths between 10−4 m and 10−3 m (100 μm and 1 mm). The term myriometre (abbr. mom, equivalent to 100 micrometres; frequently confused with the myriametre, 10 kilometres) is deprecated; the decimal metric prefix myrio- is obsolete and was not included among the prefixes when the International System of Units was introduced in 1960.

1 millimetre

The millimetre (SI symbol: mm) is a unit of length in the metric system equal to 10−3 metres (1⁄1 000 m = 0.001 m). To help compare different orders of magnitude, this section lists lengths between 10−3 m and 10−2 m (1 mm and 1 cm).

1 centimetre

The centimetre (SI symbol: cm) is a unit of length in the metric system equal to 10−2 metres (1⁄100 m = 0.01 m). To help compare different orders of magnitude, this section lists lengths between 10−2 m and 10−1 m (1 cm and 1 dm).

1 decimetre

The decimetre (SI symbol: dm) is a unit of length in the metric system equal to 10−1 metres (1⁄10 m = 0.1 m). To help compare different orders of magnitude, this section lists lengths between 10 centimetres and 100 centimetres (10−1 metre and 1 metre).

Conversions

10 centimetres (abbreviated to 10 cm) is equal to:

Wavelengths

Human-defined scales and structures

Nature

Astronomical

1 metre

To help compare different orders of magnitude, this section lists lengths between one metre and ten metres. Light, in vacuum, travels 1 metre in 1/299,792,458, or of a second.

Conversions

1 metre is:

Human-defined scales and structures

Sports

Nature

Astronomical

1 decametre

The decametre (SI symbol: dam) is a unit of length in the metric system equal to 10 metres (101 m). To help compare different orders of magnitude, this section lists lengths between 10 and 100 metres.

Conversions

10 metres (very rarely termed a decametre which is abbreviated as dam) is equal to:

Human-defined scales and structures

Sports

Nature

Astronomical

1 hectometre

The hectometre (SI symbol: hm) is a unit of length in the metric system equal to 100 metres (102 m). To compare different orders of magnitude this section lists lengths between 100 metres and 1,000 metres (1 kilometre).

Conversions

100 metres (sometimes termed a hectometre) is equal to:

Human-defined scales and structures

Sports

Nature

Astronomical

1 kilometre

The kilometre (SI symbol: km) is a unit of length in the metric system equal to 1 000 metres (103 m). To help compare different orders of magnitude, this section lists lengths between 1 kilometre and 10 kilometres (103 and 104 metres).

Conversions

1 kilometre (unit symbol km) is equal to:

Human-defined scales and structures

Nature

Geographical

Astronomical

10 kilometres (1 myriametre)

To help compare different orders of magnitude, this section lists lengths between 10 and 100 kilometres (104 to 105 metres). The myriametre (sometimes also spelled myriometre; 10,000 metres) is a deprecated unit name; the decimal metric prefix myria- (sometimes also written as myrio- ) is obsolete and was not included among the prefixes when the International System of Units was introduced in 1960.

Conversions

10 kilometres is equal to:

Sports

Human-defined scales and structures

Geographical

Astronomical

100 kilometres

A length of 100 kilometres (about 62 miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects. It is the altitude at which the FAI defines spaceflight to begin. To help compare orders of magnitude, this section lists lengths between 100 and 1,000 kilometres (105 and 106 metres).

Conversions

A distance of 100 kilometres is equal to about 62 miles (or 100 km).

Human-defined scales and structures

Geographical

Astronomical

1 megametre

The megametre (SI symbol: Mm) is a unit of length in the metric system equal to 1 000 000 metres (106 m). To help compare different orders of magnitude, this section lists lengths starting at 106 m (1 Mm or 1,000 km).

Conversions

1 megametre is equal to:

Human-defined scales and structures

Sports

Geographical

Astronomical

10 megametres

To help compare different orders of magnitude, this section lists lengths starting at 107 metres (10 megametres or 10,000 kilometres).

Conversions

10 megametres (10 Mm) is

Human-defined scales and structures

Geographical

Astronomical

100 megametres

To help compare different orders of magnitude, this section lists lengths starting at 108 metres (100 megametres or 100,000 kilometres or 62,150 miles).

1 gigametre

; lower part: their darker mirror images (artist's interpretation). The gigametre (SI symbol: Gm) is a unit of length in the metric system equal to 1 000 000 000 metres (109 m). To help compare different distances this section lists lengths starting at 109 metres (1 gigametre (Gm) or 1 billion metres).

10 gigametres

To help compare different distances this section lists lengths starting at 1010 metres (10 gigametres (Gm) or 10 million kilometres, or 0.07 astronomical units).

100 gigametres

To help compare distances at different orders of magnitude this section lists lengths starting at 1011 metres (100 gigametre or 100 million kilometres or 0.7 astronomical units).

1 terametre

The terametre (SI symbol: Tm) is a unit of length in the metric system equal to 1 000 000 000 000 metres (1012 m). To help compare different distances, this section lists lengths starting at 1012 m (1 Tm or 1 billion km or 6.7 astronomical units).

10 terametres

To help compare different distances this section lists lengths starting at 1013 m (10 Tm or 10 billion km or 67 astronomical units).

100 terametres

To help compare different distances this section lists lengths starting at 1014 m (100 Tm or 100 billion km or 670 astronomical units).

1 petametre

The petametre (SI symbol: Pm) is a unit of length in the metric system equal to 1015 metres. To help compare different distances this section lists lengths starting at 1015 m (1 Pm or 1 trillion km or 6685 astronomical units (AU) or 0.11 light-years).

10 petametres

To help compare different distances this section lists lengths starting at 1016 m (10 Pm or 66,800 AU, 1.06 light-years).

100 petametres

To help compare different distances this section lists lengths between 1017 m (100 Pm or 11 light-years) and 1018 m (106 light-years).

1 exametre

The exametre (SI symbol: Em) is a unit of length in the metric system equal to 1018 metres. To help compare different distances this section lists lengths between 1018 m (1 Em or 105.7 light-years) and 1019 m (10 Em or 1,057 light-years).

10 exametres

To help compare different orders of magnitude, this section lists distances starting at 10 Em (1019 m or 1,100 light-years).

100 exametres

To help compare different orders of magnitude, this section lists distances starting at 100 Em (1020 m or 11,000 light-years).

1 zettametre

The zettametre (SI symbol: Zm) is a unit of length in the metric system equal to 1021 metres. To help compare different orders of magnitude, this section lists distances starting at 1 Zm (1021 m or 110,000 light-years).

10 zettametres

To help compare different orders of magnitude, this section lists distances starting at 10 Zm (1022 m or 1.1 million light-years).

100 zettametres

To help compare different orders of magnitude, this section lists distances starting at 100 Zm (1023 m or 11 million light-years).

1 yottametre

The yottametre (SI symbol: Ym) is a unit of length in the metric system equal to 1024 metres. To help compare different orders of magnitude, this section lists distances starting at 1 Ym (1024 m or 105.702 million light-years).

10 yottametres

To help compare different orders of magnitude, this section lists distances starting at 10 Ym (1025 m or 1.1 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depends on the cosmological models used.

100 yottametres

To help compare different orders of magnitude, this section lists distances starting at 100 Ym (1026 m or 11 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.

1 ronnametre

The ronnametre (SI symbol: Rm) is a unit of length in the metric system equal to 1027 metres. To help compare different orders of magnitude, this section lists distances starting at 1 Rm (1027 m or 105.7 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.