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1.7 m

How Small Are You?

Scroll down to zoom from human scale to the smallest distance in physics. Each scroll covers an order of magnitude.

Human Scale
You. A human being.
1.7 meters
This is the scale you know. The world you can see, touch, and understand.
A guitar
~1 meter
A ruler
30 cm
Your hand
~10 cm
A ladybug
~1 cm
Barely Visible
1,000x smaller than you
A grain of sand
~1 mm
The smallest thing you can see with the naked eye.
A human egg cell
~100 μm
The largest cell in your body. Just barely visible as a tiny dot.
Width of a human hair
~70 μm
A red blood cell
~10 μm
You have 25 trillion of them, carrying oxygen to every cell in your body.
Microscopic
250,000x smaller than you
A red blood cell up close
7 μm
A biconcave disc, perfectly shaped to squeeze through your smallest capillaries.
E. coli bacteria
~2 μm
There are more bacteria in your gut than cells in your entire body.
The wavelength of infrared light
~1 μm
The wavelength of green light
~500 nm
This is the limit of optical microscopes. Below this, light itself is too large to reveal detail.
The smallest thing a light microscope can see
~200 nm
A coronavirus particle
~100 nm
SARS-CoV-2. Invisible to the naked eye, yet it changed the entire world.
Nanoscale
20 million times smaller than you
A virus
~80 nm
About 1,000 viruses fit across the width of a single human hair.
A cell membrane
~10 nm thick
The thin boundary that separates the inside of every cell from the outside world.
The DNA double helix
~2 nm wide
The code that builds you. Three billion base pairs, coiled into every cell of your body.
A glucose molecule
~1 nm
The fuel your cells burn for energy. One nanometer across.
Atomic
3 billion times smaller than you
A water molecule — H₂O
~0.5 nm
Three atoms held together by shared electrons. The molecule of life.
A carbon atom
~0.3 nm (154 pm)
The backbone of all organic chemistry. The atom of life.
A hydrogen atom
~120 pm
The smallest atom. One proton, one electron. The simplest thing in the universe.
The Bohr radius
53 pm
The most probable distance of the electron from the proton in a hydrogen atom.
Subatomic
1 trillion times smaller than you
1 picometer
10 −12 m
One trillionth of a meter. We are now deep inside the atom.
+
The proton
0.88 fm (8.8 × 10 −16 m)
100,000 times smaller than the atom it lives in.
"If an atom were a football stadium, the proton would be a marble at the 50-yard line. The rest is empty space."
Fundamental
+
A proton
~0.8 fm
A quark
~10 −18 m (estimated)
The building blocks of protons and neutrons. Never observed in isolation — they are always bound together by the strong nuclear force.
Below this, physics starts breaking down...
17 orders of magnitude of... nothing we can describe. No known structures exist between quarks and the Planck length.
The Planck Length
1.616 × 10 −35 meters
The smallest meaningful distance in physics. Below this, space itself may not exist as we understand it.
"Below the Planck length, the concept of 'distance' itself may not exist."
You just traveled from
1.7 meters
to
0.0000000000000000000000000000000000016 meters
The journey down is just as infinite as the journey up.
You exist at the only scale where consciousness emerges — perfectly in between.
Now go the other direction → The Size of Space

What Is How Small Are You?

How Small Are You? is a free interactive scroll-driven experience that takes you on a journey from human scale (1.7 meters) all the way down to the Planck length (1.6 × 10 −35 meters) — the smallest meaningful distance in physics. Along the way, you will encounter cells, molecules, atoms, subatomic particles, and the fundamental limits of physical reality, each shown at its correct relative scale.

How It Works

Simply scroll down to zoom into smaller and smaller scales. The experience uses a logarithmic scale, so each order of magnitude receives roughly equal scroll distance. You will pass through seven distinct levels: human scale, barely visible, microscopic, nanoscale, atomic, subatomic, and fundamental. Each level features accurate size information and fascinating context about the objects you encounter.

Frequently Asked Questions

What is the smallest thing in the universe?

The smallest meaningful distance in physics is the Planck length, approximately 1.6 × 10 −35 meters. Below this scale, our current understanding of physics breaks down. The smallest observed particles are quarks, which make up protons and neutrons, estimated at around 10 −18 meters.

How small is an atom?

A typical atom is about 1 to 3 angstroms in diameter (0.1 to 0.3 nanometers). A hydrogen atom, the smallest atom, has a radius of about 53 picometers. Atoms are roughly 100,000 times larger than their nuclei — most of an atom is empty space.

What is the Planck length?

The Planck length is approximately 1.616 × 10 −35 meters. It is derived from three fundamental constants: the gravitational constant, the speed of light, and Planck's constant. At this scale, quantum gravitational effects become significant and the concept of measurable distance may cease to exist.

Related Experiences

If you enjoyed this, try these: The Size of Space · Center of Earth · Ocean Depth · Earth in a Day

Last updated: March 2026 · whatifs.fun — Free interactive games, experiments & simulations