00WHAT THE SCIENCE SAYS

Not a teardrop.
More like a bun.

Rain falling over a grey slate rooftop and a quiet street, with individual drops caught in the light against a dark background — AI-generated image, not a photograph of a real person or place.

The classic drawn raindrop is the wrong shape.

Surface tension pulls a drop round, and the air it falls through pushes its underside flat. NASA and the US Geological Survey explain how size decides which force wins, and why the biggest drops never reach the ground whole.

ROUND TOPflat bottomUpdated 14 October 2026

Pick a drop size

01Principles

Small drops stay round
Bigger drops flatten
The biggest break apart
Two forces, one falling drop

02THE SHORT ANSWER

Size decides
the shape.

Surface tension wins in small drops.
Air pressure wins as drops grow and fall faster.

SMALL DROPS

Round as a bead

NASA says drops under about 1 mm stay roughly round, because surface tension holds them together more strongly than the air can push.

Pick a drop size

MEDIUM DROPS

Flattened like a bun

At around 2 to 3 mm, air pushing up on the falling drop flattens its bottom. The top stays rounded, like the top half of a hamburger bun.

See the numbers

BIG DROPS

Parachute, then pop

Past about 4.5 mm, a drop is pushed into a parachute shape and breaks into smaller drops. That puts a ceiling on how big a raindrop can get.

Watch for it

03A QUICK DROP CHECK

How big is
the drop?

Pick a size to see its shape and how fast it falls. The bar shows the fall speed, from drifting to fast.

Sizes and speeds are approximate, from NASA GPM, the USGS and the University of Wisconsin-Madison's weather team.

Drop check

Choose a dropA cloud dropletDrizzleA small raindropA medium raindropA very large raindrop

A cloud dropletAbout 1 cm a second

A typical cloud droplet, about 10 microns in radius, falls at roughly 1 centimetre per second, so slowly that a very gentle updraft keeps it aloft.

DrizzleUnder 0.5 mm

Drops smaller than about 0.5 mm across count as drizzle rather than rain. Drizzle is often linked with low, flat stratus cloud.

A small raindropRound, about 2 mph

Drops under about 1 mm stay nearly spherical. Smaller raindrops fall at around 2 miles per hour.

A medium raindropBun shaped

At around 2 to 3 mm, air pressure flattens the bottom of the falling drop while surface tension keeps the top rounded.

A very large raindropAbout 10 m a second

The largest raindrops fall at about 10 metres per second. Past about 4.5 mm they distort into a parachute shape and break up.

Sources: NASA GPM, Anatomy of a raindrop and How fast do raindrops fall?; University of Wisconsin-Madison SSEC, How fast do raindrops fall?

04TWO NUMBERS WORTH KNOWING

Fast drops,
and faster ones.

One figure on the top speed of rain,
one on drops that seem to break the limit.

≈ 10 m/s

Fall speed of the largest drops

NASA says fall speed rises with drop size, reaching about 10 metres per second for the largest drops. Falling from 4,000 metres would take at least 400 seconds, about seven minutes.

TOP SPEED · NASA GPM

30–60%

Tiny 0.3 mm drops falling too fast

Measuring 1.5 million raindrops, researchers found 30 to 60 percent of 0.3 mm drops fell faster than their expected terminal speed. Drops of 0.8 mm and larger fell at expected speeds.

SUPER-TERMINAL DROPS · MICHIGAN TECH

The researchers suggest these super-terminal drops may be fragments broken off larger drops, which would make rain more agitated than expected. The cause is not yet confirmed.

05THREE THINGS TO NOTICE

Next time
it rains.

You cannot see a falling drop's shape with the naked eye, but you can see the science at work in everyday rain.

Look at drops resting on a leaf
Small beads of water look round. That is surface tension pulling the water into the tightest shape it can.
Compare drizzle with a downpour
Drizzle drops are under about 0.5 mm. The largest raindrops fall at about 10 metres per second and can even compact and erode soil.
Remember the bun
When you draw rain, a rounded top and a flatter bottom is closer to the real shape of a falling drop than a pointed teardrop.

Raindrops splashing into a puddle on a paved path, with rings spreading across the water — AI-generated image, not a photograph of a real person or place.

06WHY IT MATTERS

Measuring rain
from space.

Close-up of round water droplets beaded on a green leaf after a shower — AI-generated image, not a photograph of a real person or place.

Knowing the shapes and sizes of drops helps scientists estimate rainfall. NASA explains that more accurate drop measurements improve estimates of global precipitation.

The Global Precipitation Measurement mission's Dual-frequency Precipitation Radar was designed to measure drop sizes layer by layer within clouds, as part of rain and snow data collected worldwide every three hours.

07Questions

Questions people ask

Why are raindrops drawn as teardrops?

It is a convention, not the real shape. The University of Wisconsin-Madison's weather team notes that falling raindrops flatten under air drag, so they are not teardrop shaped.

What holds a raindrop together?

NASA explains that water molecules bond to each other more strongly than to the air, and that surface tension pulls small drops into a roughly round shape.

How big can a raindrop get?

NASA says drops larger than about 4.5 mm are distorted into a parachute shape and break into smaller drops. Another NASA page puts the break-up at around 4 mm or more.

What is the difference between drizzle and rain?

Size. The University of Wisconsin-Madison's weather team says raindrops are at least 0.5 mm across, and drizzle drops are smaller than that.

How do raindrops form?

NASA says dust and smoke particles high in clouds give moisture a place to settle and form drops.

08Sources

Not a teardrop.
More like a bun.