Measured quantity · Cosmology

The Hubble Constant

Cosmology & UniverseEstablished Science

Definition

The present-day rate of expansion of the Universe, denoted H₀.

Scientific overview

The Hubble constant sets the current expansion rate and, with it, the scale and age of the Universe. It is measured in kilometres per second per megaparsec.

Current measurements

From the CMB (early Universe)	67.4 ± 0.5 km/s/Mpc	Planck Collaboration
From the local distance ladder	≈ 73 km/s/MpcSH0ES / Cepheid + Type Ia supernovae	NASA

Measured by

Planck

Hubble Space Telescope

DESI (Dark Energy Spectroscopic Instrument)

The Hubble–Lemaître Law

The Hubble Tension

The Expansion of the Universe

Knowledge connections

Related toThe Expansion of the Universe
Related toThe Hubble–Lemaître Law
Related toThe Hubble–Lemaître Law
Related toThe Hubble Tension
Related toThe Expansion of the Universe
Measured byPlanck
Measured byHubble Space Telescope
Measured byDESI (Dark Energy Spectroscopic Instrument)
Related toThe Hubble Tension
Required byThe Age of the Universe
Associated withRedshift & the Hubble–Lemaître Law
Associated withThe Cosmic Distance Ladder
Associated withTip of the Red Giant Branch
Associated withWater Megamaser Distances
Associated withStandard Sirens
Associated withSH0ES
Associated withHubble Distance

Sources & references

Facts on this topic will be cited from these primary and reference sources.

Planck CollaborationESA Planck mission / Planck Collaboration
Cosmic microwave background maps and the cosmological parameters of the ΛCDM model.
NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.

Quick facts

Type: Measured quantity
Field: Cosmology
Consensus: Established Science

Scientific consensus

Established Science

Observationally confirmed and consistent across all leading models.

Quality & authority

38%

Unreviewed

Completeness: Complete
Source coverage: Complete
Citation coverage: None
Relationship coverage: Complete
Review coverage: None
Image coverage: None

Curated from authoritative sources. See source quality.

Scientific citations

Real, source-backed references — primary papers first, then datasets and institutional sources. Formatted through the citation engine; nothing is fabricated.

Peer-reviewed paperPlanck 2018 results. VI. Cosmological parameters

Planck Collaboration · Astronomy & Astrophysics 641, A6 · 2020

ESA — Planck Collaboration · doi:10.1051/0004-6361/201833910

Cite (APA / BibTeX)

Planck Collaboration (2020). Planck 2018 results. VI. Cosmological parameters. Astronomy & Astrophysics 641, A6. ESA — Planck Collaboration. https://doi.org/10.1051/0004-6361/201833910

@misc{cite:planck-2018-cosmological-parameters,
  title        = {Planck 2018 results. VI. Cosmological parameters},
  author       = {Planck Collaboration},
  organization = {ESA — Planck Collaboration},
  howpublished = {Astronomy & Astrophysics 641, A6},
  year         = {2020},
  doi          = {10.1051/0004-6361/201833910},
  url          = {https://doi.org/10.1051/0004-6361/201833910},
  note         = {Cosmological parameters from the final Planck data release.}
}

Mission pagePlanck — ESA Science

European Space Agency

Cite (APA / BibTeX)

European Space Agency (n.d.). Planck — ESA Science. European Space Agency. https://www.esa.int/Science_Exploration/Space_Science/Planck

@misc{cite:esa-planck,
  title        = {Planck — ESA Science},
  organization = {European Space Agency},
  year         = {n.d.},
  url          = {https://www.esa.int/Science_Exploration/Space_Science/Planck},
  note         = {ESA Planck mission — high-precision CMB maps.}
}

Institutional pageThe Hubble Constant — NASA Universe

NASA

Cite (APA / BibTeX)

NASA (n.d.). The Hubble Constant — NASA Universe. NASA. https://science.nasa.gov/

@misc{cite:nasa-cosmo-the-hubble-constant,
  title        = {The Hubble Constant — NASA Universe},
  organization = {NASA},
  year         = {n.d.},
  url          = {https://science.nasa.gov/},
  note         = {NASA science overview: The Hubble Constant.}
}

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Sources & references

Facts on this topic will be cited from these primary and reference sources.

Planck CollaborationESA Planck mission / Planck Collaboration

Cosmic microwave background maps and the cosmological parameters of the ΛCDM model.

NASANational Aeronautics and Space Administration

Mission data, planetary science, space telescopes, and public-domain imagery.

Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.

Planck Collaboration (2020). Planck 2018 results. VI. Cosmological parameters. Astronomy & Astrophysics 641, A6. ESA — Planck Collaboration. https://doi.org/10.1051/0004-6361/201833910 @misc{cite:planck-2018-cosmological-parameters, title = {Planck 2018 results. VI. Cosmological parameters}, author = {Planck Collaboration}, organization = {ESA — Planck Collaboration}, howpublished = {Astronomy & Astrophysics 641, A6}, year = {2020}, doi = {10.1051/0004-6361/201833910}, url = {https://doi.org/10.1051/0004-6361/201833910}, note = {Cosmological parameters from the final Planck data release.} }

European Space Agency (n.d.). Planck — ESA Science. European Space Agency. https://www.esa.int/Science_Exploration/Space_Science/Planck @misc{cite:esa-planck, title = {Planck — ESA Science}, organization = {European Space Agency}, year = {n.d.}, url = {https://www.esa.int/Science_Exploration/Space_Science/Planck}, note = {ESA Planck mission — high-precision CMB maps.} }

NASA (n.d.). The Hubble Constant — NASA Universe. NASA. https://science.nasa.gov/ @misc{cite:nasa-cosmo-the-hubble-constant, title = {The Hubble Constant — NASA Universe}, organization = {NASA}, year = {n.d.}, url = {https://science.nasa.gov/}, note = {NASA science overview: The Hubble Constant.} }

The Hubble Constant

Definition

Scientific overview

Current measurements

Measured by

Related topics

Knowledge connections

Sources & references

The Hubble Constant

Definition

Scientific overview

Current measurements

Measured by

Related topics

Knowledge connections

Sources & references