How big is everything? 108 sizes, smallest to largest
The sizes of all 108 things in How Big?, from the smallest length in physics to the observable universe — grouped into the 20 chapters you travel through, each with an everyday comparison. Open any name for its own page, or zoom through them all.
Start exploringChapter 1 · The Planck Scale
Down here, space and time themselves may churn into a quantum foam. No experiment has come anywhere close to probing this deep — everything at this scale is pure theory.
- Planck length1.6 × 10⁻³⁵ m · ≈ 6,630,000,000,000 trillion times smaller than a hydrogen atom
The smallest length physics can meaningfully describe. Below it, the very idea of distance may stop making sense.
Chapter 2 · Inside the Nucleus
Protons and neutrons are made of quarks, bound by the strong force — the most powerful force in nature, over a hundred times stronger than electromagnetism.
- Quark (upper limit)1.0 × 10⁻¹⁸ m · ≈ 106 million times smaller than a hydrogen atom
Quarks are the building blocks of protons and neutrons. Experiments show they're smaller than this — they may have no size at all.
- Proton1.7 fm · ≈ 62,400 times smaller than a hydrogen atom
Found in the heart of every atom. Each proton is made of three quarks, glued together by particles called gluons.
- Helium nucleus3.4 fm · ≈ 31,200 times smaller than a hydrogen atom
Two protons and two neutrons. Most of the helium in the universe was forged in the first few minutes after the Big Bang.
- Uranium nucleus15 fm · ≈ 7,070 times smaller than a hydrogen atom
92 protons and about 146 neutrons, packed so tightly that splitting them apart releases enormous energy — the idea behind nuclear power.
Chapter 4 · Atoms & Molecules
Everything you've ever touched is built from about 90 natural kinds of atom, snapped together into molecules.
- Hydrogen atom106 pm · ≈ 1 times smaller than a hydrogen atom
One proton, one electron. If the nucleus were a marble, the whole atom would be about a kilometre wide.
- Water molecule275 pm · ≈ 2.6 hydrogen atoms
One oxygen and two hydrogens. A single drop of water holds about 1.7 sextillion of them.
- Gold atom288 pm · ≈ 2.7 hydrogen atoms
Gold is so soft that a single gram can be hammered into a sheet about one square metre in size.
- Glucose molecule900 pm · ≈ 8.5 hydrogen atoms
The sugar your cells burn for fuel. Your brain alone uses around 120 grams of it every day.
Chapter 5 · The Machinery of Life
Proteins, DNA and viruses work at this scale — machines so small that visible light is too coarse to see them clearly.
- DNA (width)2 nm · ≈ 18.9 hydrogen atoms
Your DNA is only this wide, yet uncoiled from just one cell it would stretch about 2 metres.
- Haemoglobin5.5 nm · ≈ 51.9 hydrogen atoms
The protein that carries oxygen around your body. Each red blood cell holds about 270 million of them.
- Antibody12 nm · ≈ 113 hydrogen atoms
Y-shaped proteins your immune system makes to tag invaders. Each kind grabs onto one specific target.
- Ribosome25 nm · ≈ 236 hydrogen atoms
The cell's protein factory. It reads genetic instructions and builds proteins one building block at a time.
- Coronavirus90 nm · ≈ 849 hydrogen atoms
The virus behind COVID-19. Its crown of spike proteins gave coronaviruses their name — ‘corona’ is Latin for crown.
- Flu virus120 nm · ≈ 1,130 hydrogen atoms
Too small for ordinary microscopes. It works by hijacking your cells and forcing them to make copies of itself.
- Wavelength of green light530 nm · ≈ 5,000 hydrogen atoms
Things much smaller than this can't be seen clearly with a light microscope — the light waves are simply too big.
- Mimivirus750 nm · ≈ 7,080 hydrogen atoms
A giant virus, bigger than some bacteria. Scientists first mistook it for a bacterium; it was only recognised as a virus in 2003.
Chapter 6 · Under the Microscope
Cells and bacteria rule here. Your body is built from roughly 30 trillion cells — and carries about as many bacteria.
- E. coli bacterium2 µm · ≈ 18,900 hydrogen atoms
A common gut bacterium. In good conditions it can divide every 20 minutes.
- Platelet2.5 µm · ≈ 23,600 hydrogen atoms
Tiny cell fragments that rush to plug a cut and help your blood clot.
- Red blood cell7.5 µm · ≈ 70,800 hydrogen atoms
You have around 25 trillion of them, and each one lives for about 120 days.
- White blood cell12 µm · ≈ 113,000 hydrogen atoms
Your body's patrol. Neutrophils, the most common kind, hunt down and swallow bacteria.
- Skin cell30 µm · ≈ 283,000 hydrogen atoms
You shed tens of thousands of skin cells every minute — a lot of household dust is old skin.
- Sunflower pollen35 µm · ≈ 330,000 hydrogen atoms
Sunflower pollen is covered in tiny spikes that help it cling to visiting bees.
Chapter 7 · The Edge of Sight
Around a tenth of a millimetre, things finally become visible to the naked eye — just barely.
- Human hair (width)70 µm · ≈ 660,000 hydrogen atoms
Hair ranges from about 17 to 180 micrometres thick. This is a typical strand, seen end-on.
- Human egg cell120 µm · ≈ 1.7 human hairs (width)
The largest cell in the human body — just about visible without a microscope.
- Paramecium220 µm · ≈ 3.1 human hairs (width)
A single-celled swimmer covered in thousands of tiny hairs called cilia, which beat like oars.
- Dust mite250 µm · ≈ 3.6 human hairs (width)
Tiny relatives of spiders that live in beds and pillows, feeding on flakes of skin.
- Tardigrade450 µm · ≈ 6.4 human hairs (width)
Nicknamed ‘water bears’, they can survive freezing, boiling, radiation and even the vacuum of space.
- Grain of sand600 µm · ≈ 8.6 human hairs (width)
Sand is defined by size: anything from 0.0625 to 2 millimetres across.
- Mustard seed1.5 mm · ≈ 21.4 human hairs (width)
A staple of Indian tadka. Each seed is only about 1 to 2 mm across.
Chapter 8 · Small Wonders
Insects, coins and the tiniest birds. The scale of things you can hold between your fingers.
- Grain of rice7 mm · ≈ 100 human hairs (width)
Rice is the main food for more than half the people on Earth.
- Honeybee1.5 cm · ≈ 2.1 grains of rice
A honeybee beats its wings about 230 times a second — that's what makes the buzz.
- ₹10 coin2.7 cm · ≈ 3.9 grains of rice
India's two-coloured ₹10 coin is 27 mm across and weighs about 7.7 grams.
- Bee hummingbird5.5 cm · ≈ 7.9 grains of rice
The world's smallest bird, from Cuba. It weighs under 2 grams — less than a ₹10 coin.
- Cricket ball7.2 cm · ≈ 10.3 grains of rice
A men's cricket ball must weigh between 155.9 and 163 grams.
- Cutting chai glass9 cm · ≈ 12.9 grains of rice
A ‘cutting’ is half a cup of tea, served in a small ridged glass across India.
- Smartphone15 cm · ≈ 21.4 grains of rice
A modern phone is millions of times more powerful than the computer that guided Apollo 11 to the Moon.
Chapter 9 · Human Scale
The world we live in: things we can lift, ride and walk beside.
- Masala dosa40 cm · ≈ 57.1 grains of rice
A crisp rice-and-lentil crêpe wrapped around spiced potato — a South Indian classic, often 30 to 45 cm long.
- Cricket bat96.5 cm · ≈ 138 grains of rice
The Laws of Cricket cap a bat's length at 38 inches (96.5 cm).
- Human1.7 m · ≈ 243 grains of rice
You are here! On this journey, you're actually closer in scale to the biggest things than to the smallest.
- Hatchback car3.85 m · ≈ 2.3 people
The most common car shape on Indian roads, usually about 3.8 to 4 metres long.
- Giraffe5.5 m · ≈ 3.2 people
The tallest animal alive. Its long neck has just seven bones — the same number as yours.
Chapter 10 · Giants
The largest animals ever to live top out here — alongside trains, palms and the gateways we build.
- Tyrannosaurus rex12.3 m · ≈ 7.2 people
One of the biggest meat-eating dinosaurs, up to about 12 metres long. It lived around 66 to 68 million years ago.
- Cricket pitch20.1 m · ≈ 11.8 people
22 yards (20.12 m) from stump to stump — unchanged since the 1700s.
- Train coach23.5 m · ≈ 1.2 cricket pitches
Modern Indian Railways LHB coaches are about 23.5 metres long, and a train can have over 20 of them.
- Coconut palm25 m · ≈ 1.2 cricket pitches
Coconut palms can grow 25 to 30 metres tall, and a single tree can bear dozens of coconuts a year.
- Gateway of India26 m · ≈ 1.3 cricket pitches
Mumbai's waterfront arch, about 26 metres tall, completed in 1924.
- Blue whale30 m · ≈ 1.5 cricket pitches
The largest animal that has ever lived, reaching up to about 30 metres long.
- Lotus Temple34.3 m · ≈ 1.7 cricket pitches
Delhi's Bahá'í House of Worship is shaped like a lotus with 27 marble petals, rising about 34 metres.
- India Gate42 m · ≈ 2.1 cricket pitches
A 42-metre war memorial in New Delhi honouring Indian soldiers who died in the First World War.
Chapter 11 · Monuments
The tallest things humans have ever built. Even the Burj Khalifa is less than a kilometre high.
- Charminar56 m · ≈ 2.8 cricket pitches
Hyderabad's landmark, built in 1591. Each of its four minarets rises about 56 metres.
- Boeing 74770.7 m · ≈ 3.5 cricket pitches
The original ‘jumbo jet’ is about 71 metres long. It first flew in 1969.
- Qutub Minar72.5 m · ≈ 3.6 cricket pitches
Delhi's 72.5-metre minaret, begun in the late 1100s, is the tallest brick minaret in the world.
- Taj Mahal73 m · ≈ 3.6 cricket pitches
The Taj Mahal rises about 73 metres. Building it took around 20 years and some 20,000 workers.
- International Space Station109 m · ≈ 5.4 cricket pitches
About the size of a football pitch, it circles Earth roughly every 90 minutes.
- Statue of Unity182 m · ≈ 9 cricket pitches
The world's tallest statue, standing 182 metres high in Gujarat.
- Titanic269 m · ≈ 13.4 cricket pitches
The famous ocean liner was about 269 metres long. It sank on its first voyage in 1912.
- Eiffel Tower330 m · ≈ 16.4 cricket pitches
About 330 metres tall — and it grows up to 15 cm in summer as the iron expands in the heat.
Chapter 12 · Landscapes
Clouds, mountains, ocean trenches and cities. Yet shrink Earth to the size of a billiard ball and it would be smoother than one.
- Cumulus cloud1 km · ≈ 49.7 cricket pitches
Fluffy as it looks, a typical kilometre-wide cloud holds around 500 tonnes of water.
- Bandra–Worli Sea Link5.6 km · ≈ 278 cricket pitches
Mumbai's cable-stayed bridge stretches about 5.6 km across the sea.
- Mount Everest8.85 km · ≈ 440 cricket pitches
The highest point above sea level on Earth: 8,849 metres.
- Dinosaur-killing asteroid10 km · ≈ 497 cricket pitches
The asteroid that wiped out the dinosaurs 66 million years ago was roughly 10 km wide.
- Mariana Trench (depth)10.9 km · ≈ 1.2 Mount Everests
The deepest point in the ocean. Drop Everest in and its peak would still be about 2 km underwater.
- Bengaluru (across)30 km · ≈ 3.4 Mount Everests
Bengaluru's city limits stretch roughly 30 km across — home to more than 13 million people in the wider metro area.
- Marathon42.2 km · ≈ 4.8 Mount Everests
A marathon is exactly 42.195 km — a distance fixed at the 1908 London Olympics.
- Edge of space (Kármán line)100 km · ≈ 11.3 Mount Everests
About 100 km up — the commonly used boundary where space begins.
Chapter 13 · Countries & Worlds
India alone is almost as wide as the Moon. Our whole planet is small enough to circle in a couple of long-haul flights.
- Ceres940 km · ≈ 106 Mount Everests
The largest object in the asteroid belt, about 940 km across. It's classed as a dwarf planet.
- Pluto2,380 km · ≈ 269 Mount Everests
A dwarf planet with a giant heart-shaped plain of frozen nitrogen, about 2,377 km across.
- River Ganga2,530 km · ≈ 285 Mount Everests
The Ganga flows about 2,525 km from the Himalayas to the Bay of Bengal.
- India (north to south)3,210 km · ≈ 363 Mount Everests
From Kashmir to Kanyakumari, India stretches about 3,214 km.
- The Moon3,470 km · ≈ 393 Mount Everests
A little over a quarter as wide as Earth. It drifts about 3.8 cm farther away from us every year.
- Mars6,780 km · ≈ 766 Mount Everests
Home to Olympus Mons, a volcano about two and a half times taller than Everest.
- Earth12,700 km · ≈ 1,440 Mount Everests
Our home. Light could travel around it about 7.5 times in a single second.
Chapter 14 · Giant Planets
Gas giants dwarf the rocky worlds. Jupiter is so massive that it and the Sun orbit a point just outside the Sun's surface.
- Neptune49,200 km · ≈ 3.9 Earths
The windiest planet in the solar system, with gusts of over 2,000 km/h.
- Saturn116,000 km · ≈ 9.1 Earths
Saturn is so light for its size that it would float in a big enough bathtub of water.
- Earth → Moon distance384,000 km · ≈ 30.2 Earths
All the other planets in the solar system could fit side by side in this gap.
Chapter 15 · Stars
Stars come in a staggering range of sizes. Some giants could swallow hundreds of millions of Suns.
- Sagittarius A* (black hole)24 million km · ≈ 17.2 Suns
The supermassive black hole at the centre of our galaxy, with about 4 million times the Sun's mass.
- Arcturus35 million km · ≈ 25.2 Suns
An orange giant 37 light-years away — a preview of what our Sun will become in about 5 billion years.
- Earth → Sun distance150 million km · ≈ 108 Suns
Sunlight takes about 8 minutes and 20 seconds to reach us.
- Betelgeuse1.06 billion km · ≈ 762 Suns
A red supergiant in Orion. Put it where the Sun is and it would swallow everything out past Mars.
Chapter 16 · The Solar System
Our solar system is mostly empty space. Sunlight takes over four hours just to reach Neptune.
- Neptune's orbit9 billion km · ≈ 6,470 Suns
Neptune takes about 165 years to travel once around the Sun.
Chapter 17 · Between the Stars
Stars are scattered unimaginably thinly. Even the nearest one is about 100 million times farther away than the Moon.
- One light-year1 light-years · ≈ 1,050 Solar Systems (to Neptune)
The distance light travels in a year: about 9.46 trillion km.
- Distance to nearest star4.24 light-years · ≈ 4,460 Solar Systems (to Neptune)
Proxima Centauri, the closest star to the Sun, is 4.24 light-years away.
- Orion Nebula24 light-years · ≈ 25,200 Solar Systems (to Neptune)
A stellar nursery where new stars are being born. You can see it with the naked eye as a fuzzy patch in Orion's sword.
- Omega Centauri150 light-years · ≈ 158,000 Solar Systems (to Neptune)
A ball of about 10 million stars — the biggest star cluster in the Milky Way.
Chapter 18 · Galaxies
Galaxies are islands of hundreds of billions of stars — and there may be hundreds of billions of galaxies out there.
- Large Magellanic Cloud31,700 light-years · ≈ 33.3 million Solar Systems (to Neptune)
A small galaxy orbiting our own, visible from the southern hemisphere as a faint cloud in the sky.
- Milky Way100,000 light-years · ≈ 105 million Solar Systems (to Neptune)
Our galaxy: about 100,000 light-years across, with 100 to 400 billion stars. The Sun is one of them.
- Andromeda Galaxy220,000 light-years · ≈ 2.2 Milky Ways
Our nearest big neighbour, with about a trillion stars. It's heading our way and may collide with the Milky Way in a few billion years.
Chapter 19 · Groups & Clusters
Gravity gathers galaxies into groups and clusters, bound together across millions of light-years.
- Distance to Andromeda2.54 million light-years · ≈ 25.4 Milky Ways
The Andromeda Galaxy is the most distant thing most people can see with the naked eye.
- Local Group10 million light-years · ≈ 100 Milky Ways
Our galactic neighbourhood: dozens of galaxies, including the Milky Way and Andromeda.
- Virgo Cluster14.8 million light-years · ≈ 148 Milky Ways
More than 1,300 galaxies swarming together about 54 million light-years away.
Chapter 20 · The Cosmic Web
On the largest scales, galaxies trace a vast web of filaments around enormous empty voids. This is the biggest structure there is.
- Boötes Void328 million light-years · ≈ 3,280 Milky Ways
A vast, nearly empty region about 330 million light-years across, with only a few dozen galaxies inside.
- Laniakea Supercluster518 million light-years · ≈ 5,180 Milky Ways
Our home supercluster. Its name means ‘immeasurable heaven’ in Hawaiian, and it contains around 100,000 galaxies.
- Observable universe93 billion light-years · ≈ 930,000 Milky Ways
Everything we could ever see — about 93 billion light-years across. Light from beyond hasn't had time to reach us yet.
Sizes are rounded, typical values drawn from standard reference sources, including NIST/CODATA physical constants and NASA's planetary fact sheets. Real objects vary; see About for how sizes are chosen.