Scale Explorer
One continuous zoom across about 62 orders of magnitude, from the Planck length to the edge of the observable universe. Every object is drawn at its true size relative to the others.
Scroll, pinch or drag sideways to zoom · tap an object for details · dots inside are not to scale
Human
Height: ≈ 1.7 m
An adult is about 1.7 m tall, which is roughly 10³⁵ Planck lengths.
Source: NCD-RisC, eLife 5, e13410 (2016)
Every object, its size and its source
The values drawn in the zoom above. "≈" marks sizes that vary or are estimates; the line under each name says what is measured (radius, diameter, height, width, length or distance).
| Object | Size | Power of ten | Source |
|---|---|---|---|
| Planck length Length | 1.616 × 10⁻³⁵ m | 10⁻³⁵ m | CODATA 2022 (NIST) |
| Quark Radius (upper limit) | < 430 zm | 10⁻¹⁹ m | ZEUS Collaboration, Phys. Lett. B 757, 468 (2016) |
| Proton Radius | 840.8 am | 10⁻¹⁶ m | CODATA 2022 (NIST) |
| Hydrogen atom Radius | 52.92 pm | 10⁻¹¹ m | CODATA 2022 (NIST) |
| DNA double helix Width | ≈ 2 nm | 10⁻⁹ m | Watson & Crick, Nature 171, 737 (1953) |
| Coronavirus (SARS-CoV-2) Diameter | ≈ 100 nm | 10⁻⁷ m | Bar-On et al., eLife 9, e57309 (2020) |
| Red blood cell Diameter | ≈ 7.8 µm | 10⁻⁶ m | R. Milo & R. Phillips, Cell Biology by the Numbers (2015); Sender et al., PLoS Biol 14, e1002533 (2016) |
| Human hair (width) Width | ≈ 90 µm | 10⁻⁵ m | The Physics Factbook — Diameter of a Human Hair (17–181 µm); U.S. NNI: 80,000–100,000 nm |
| Ant (black garden ant) Length | ≈ 4 mm | 10⁻³ m | AntWiki — Lasius niger |
| Human Height | ≈ 1.7 m | 10⁰ m | NCD-RisC, eLife 5, e13410 (2016) |
| Blue whale Length | ≈ 30 m | 10¹ m | NOAA Fisheries — Blue Whale |
| Burj Khalifa Height | 828 m | 10² m | CTBUH Skyscraper Center — Burj Khalifa |
| Mount Everest Height | 8.849 km | 10³ m | China–Nepal joint survey (2020): 8,848.86 m |
| Moon Diameter | 3.475 Mm | 10⁶ m | NASA Planetary Fact Sheets |
| Earth Diameter | 12.74 Mm | 10⁷ m | NASA Planetary Fact Sheets |
| Jupiter Diameter | 143 Mm | 10⁸ m | NASA Planetary Fact Sheets |
| Sun Diameter | 1.391 Gm | 10⁹ m | IAU 2015 Resolution B3 (nominal solar radius) |
| Betelgeuse Diameter | ≈ 1.063 Tm | 10¹² m | Joyce et al., ApJ 902, 63 (2020) |
| Neptune's orbit Diameter | 8.997 Tm | 10¹² m | NASA Planetary Fact Sheets |
| Light-year Length | 9.461 Pm | 10¹⁵ m | IAU — light-year = c × 1 Julian year (365.25 d) |
| Oort cloud Diameter | ≈ 29.92 Pm | 10¹⁶ m | NASA Science — Oort Cloud (outer edge ≈ 100,000 au) |
| Distance to Proxima Centauri Distance | 40.17 Pm | 10¹⁶ m | Gaia DR3 (ESA): Proxima Centauri parallax 768.07 mas |
| Milky Way Diameter | ≈ 946.1 Em | 10²⁰ m | NASA Science — Milky Way (≈ 100,000 ly across) |
| Distance to Andromeda Distance | ≈ 23.65 Zm | 10²² m | NASA — Andromeda Galaxy (M31), ≈ 2.5 million ly |
| Local Group Diameter | ≈ 94.61 Zm | 10²² m | NASA Imagine the Universe — The Local Group |
| Laniakea Supercluster Diameter | ≈ 4.937 Ym | 10²⁴ m | Tully et al., Nature 513, 71 (2014) |
| Observable universe Diameter | ≈ 880 Ym | 10²⁶ m | Planck Collaboration, A&A 641, A6 (2020) — ΛCDM horizon |
About the Scale Explorer
The Scale Explorer is an interactive journey across the sizes of the universe, from the smallest subatomic particles to the largest cosmic structures. By scrolling, you zoom smoothly through powers of ten, watching atoms give way to cells, humans, mountains, planets, stars and galaxies. Because each step multiplies the previous size by ten, the tool reveals just how vast the gap is between the quantum world and the cosmos. It is a visual, intuitive way to grasp orders of magnitude, a concept that underpins all of science but is hard to feel from numbers alone.
How to use it
- Start at human scale, the familiar middle ground of about one meter.
- Zoom in (scroll up, pinch out, or drag right) to shrink toward cells, molecules, atoms, quarks and the Planck length.
- Zoom out (scroll down, pinch in, or drag left) to grow toward mountains, planets, stars, galaxies and the observable universe.
- Tap any object, or press Tour, to read its size, a one-line fact and the source of the number.
The science behind it
Sizes in nature span more than 60 orders of magnitude, far too wide for a linear ruler. The Scale Explorer instead uses a logarithmic scale, where each equal step represents a tenfold change. This is the same idea behind scientific notation (1 x 10^-10 m for an atom, 1 x 10^21 m for a galaxy) and behind familiar log scales like decibels and the Richter scale. Seeing the universe this way reveals the true distances: a human is about 10 tenfold steps above an atom, but a galaxy is about 21 steps above a human.
Frequently asked questions
What is an order of magnitude?
It is a factor of ten. Each order of magnitude means something is ten times larger or smaller, so a few steps cover enormous size differences.
Why use a logarithmic scale?
Because real sizes range from particles to galaxies. A linear scale could not show both at once, but a log scale fits all of them into one smooth journey.
What is the smallest and largest thing shown?
The smallest is the Planck length, about 1.6 × 10⁻³⁵ m; the largest is the observable universe, about 8.8 × 10²⁶ m across. That is about 62 orders of magnitude.
Is this good for learning?
Yes. Visualizing scale builds the number sense students need in physics, biology and astronomy, where powers of ten appear everywhere.
Keep exploring
After exploring scale, use the length and area converters to put exact numbers to any object you saw. For more on the same idea, try Guess the Size to test your size intuition, or the inventions and history timelines to travel through time as well as space.
Embed this tool
Embed this tool on your own site for free. An attribution link is included.
Sources
Derived numbers in the facts (ratios, light travel times) are computed from these values. The observable universe's radius (≈ 4.4 × 10²⁶ m) is the comoving particle horizon in the Planck 2018 ΛCDM model.
- CODATA 2022 (NIST)
- ZEUS Collaboration, Phys. Lett. B 757, 468 (2016)
- Watson & Crick, Nature 171, 737 (1953)
- Bar-On et al., eLife 9, e57309 (2020)
- R. Milo & R. Phillips, Cell Biology by the Numbers (2015); Sender et al., PLoS Biol 14, e1002533 (2016)
- The Physics Factbook — Diameter of a Human Hair (17–181 µm); U.S. NNI: 80,000–100,000 nm
- AntWiki — Lasius niger
- NCD-RisC, eLife 5, e13410 (2016)
- NOAA Fisheries — Blue Whale
- CTBUH Skyscraper Center — Burj Khalifa
- China–Nepal joint survey (2020): 8,848.86 m
- NASA Planetary Fact Sheets
- IAU 2015 Resolution B3 (nominal solar radius)
- Joyce et al., ApJ 902, 63 (2020)
- IAU — light-year = c × 1 Julian year (365.25 d)
- NASA Science — Oort Cloud (outer edge ≈ 100,000 au)
- Gaia DR3 (ESA): Proxima Centauri parallax 768.07 mas
- NASA Science — Milky Way (≈ 100,000 ly across)
- NASA — Andromeda Galaxy (M31), ≈ 2.5 million ly
- NASA Imagine the Universe — The Local Group
- Tully et al., Nature 513, 71 (2014)
- Planck Collaboration, A&A 641, A6 (2020) — ΛCDM horizon