Skip the zoom and go to the reference

Size, from the universe to the Planck length

What scale are we working in?

Every project has a size. A delivery route, a warehouse, a machined part, a bacterium on a cutting board. Scroll to fall from the edge of the observable universe to the smallest length physics has a name for: about 62 powers of ten, with everything drawn to scale against everything else.

What you do
Scroll down to zoom in, up to zoom out. Drag the ruler on the right to fly.
Find your size
Type a size like 3 mm, 0.005 in or 2 miles, or a thing like hair. A gold dashed line marks your size.
How to read it
The big number is how wide your screen is right now. Every outline shares one centre, so sizes compare directly.

Galaxies

This screen is 334 billion light-yearswide

1.1 × 1027 m

Observable universe

about 93 billion light-years

Everything light has had time to reach us from. The whole universe may be far larger. Scroll down to zoom in.

Which scale is your project in?

Most work lives in one band and borrows a unit from the band below it for tolerances. Pick the band, then zoom there to see what else is that size.

  • Thousands of kilometres1,000 to 10,000 km

    Supply chains, freight lanes, time zones. The contiguous United States is about 4,500 km (2,800 miles) wide.

  • Kilometres1 to 100 km

    Delivery routes, service areas, farms and towns. A mile is 1.609 km; a marathon is 42.195 km.

  • Metres1 to 100 m

    Rooms, warehouses, trucks, pallets and people. A 53 ft trailer is 16.2 m long; a pallet is 1.22 m by 1.02 m.

  • Centimetres1 to 100 cm

    Products, packaging, labels and screens. An inch is exactly 25.4 mm.

  • Millimetres0.5 to 10 mm

    Parts, fasteners, woodwork and print. A sixteenth of an inch is 1.59 mm; a credit card is 0.76 mm thick.

  • Fractions of a millimetre20 to 500 µm

    Machining tolerances, paper and film thickness, coatings. One thou (0.001 in) is 25.4 µm, about a third of a hair.

  • Micrometres1 to 20 µm

    Bacteria, blood cells, dust and filters. An E. coli bacterium is about 2 µm long. A micrometre is also called a micron.

  • Hundreds of nanometres100 to 1,000 nm

    Light, viruses and fine filtration. A light microscope cannot show detail much smaller than about 200 nm.

  • Nanometres1 to 100 nm

    Chips, molecules and thin films. Transistors on a leading-edge chip sit 45 to 50 nm apart, whatever the node is called.

  • Below a nanometre0.1 to 1 nm

    Atoms, and the chemistry and materials science that work with them. A hydrogen atom is about 0.1 nm across.

Everything on the page, biggest to smallest

“About” marks a typical value for something that varies. Exact values come from a definition or a standard.

ThingSizeZoom

What this page leaves out

  • It is not a map. Every outline is drawn around the same centre so sizes compare directly. The Sun is not at the centre of the galaxy, and a blood cell is not inside a hair.
  • Living things vary. Hairs, cells, whales and pollen come in a range of sizes. The drawing uses a typical value and the table says so.
  • Some things have no measured size. Quarks and electrons behave like points in every experiment so far. The dashed outline for a quark is an upper limit: if it has a size, it is smaller than that.
  • The Planck length is not proven to be a pixel. It is the scale where gravity and quantum effects should both matter and no tested theory describes what happens. Experiments stop about 16 powers of ten above it.
  • The observable universe is only the part we can see. It is the region light has had time to reach us from. The whole universe may be much larger.
  • The scroll speeds up in the empty stretch. Between about 10−19 m and 10−34 m nothing is known to exist, so each power of ten takes less scrolling there. The ruler on the right still counts every one.

How the numbers were checked

Every figure was checked against a published source on 2 November 2026. Sizes come from definitions and standards where one exists, and otherwise from the measuring body. Things that vary in nature are marked “about”, and the drawing uses a typical value.

Physics and units: NIST CODATA 2022 (proton radius, Planck length, Bohr radius, silicon lattice); the inch and mile as fixed in 1959; BIPM, 27th CGPM, for the 2022 prefixes ronna, quetta, ronto and quecto; Particle Data Group 2024 W boson mass, for the reach of the weak force; ZEUS Collaboration 2016 and L3 at LEP, for the quark radius limit. Space: NASA planetary fact sheets; IAU 2012 (the AU) and IAU 2015 (the Sun’s nominal radius); JPL Horizons, for Voyager 1’s distance on 2 November 2026; Tully and colleagues 2014 in Nature (Laniakea); GRAVITY Collaboration 2021 (distance to the galactic centre); Gaia DR3 (Proxima Centauri). Earth and objects: the 2020 China and Nepal Everest survey; CTBUH (Burj Khalifa); World Aquatics facility rules; NFL rulebook; ISO 668 (containers), ISO/IEC 7810 (cards), ISO 6780 (pallets); USGA equipment rules; US Mint coin specifications; CDC National Center for Health Statistics, 2021 to 2023 (adult height). Life and materials: US EPA and DOE (HEPA rating, hair width); BioNumbers (hemoglobin, E. coli); published haematology ranges (red blood cells); WikiChip and SemiWiki on TSMC N3 and Intel 4 (gate pitch).

Voyager 1 moves about 3.6 AU a year, so its line will drift out of date. The rest will not.

Highland Willow, 2 November 2026.

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