速 (sù) is a Chinese character meaning “fast”. It is written from 辶 (walk; go — the "movement" radical (chuò)) and 束 (a bundle; to tie up), one enclosing the other, and takes 10 strokes.
Build the character for “fast; speed”
Four steps: break it apart, build it, recall it, use it in a word.
StartLearn this character
Structure
辶 + 束
Enclosing structure
Structure from: 说文解字: 速，疾也。从辵束聲；IDS 拆分 ⿺辶束，并以 hanzi-writer-data 笔画核验：笔画 0–6 与「束」逐笔对应，笔画 7–9 为「辶」（点、横折折撇、平捺）
Memory aid
束 is a bundle, tied up tight so nothing slows you down. Carry it along the road radical 辶 and you travel at speed: 速.
This is a memory aid, not the historical origin.
Stroke order
10 strokes
In real words
- 速度sù dùspeed; velocity; pace速 = sù
- 迅速xùn sùrapid; swift; speedy速 = sù
- 匀速yún sùuniform speed; constant velocity速 = sù
Go deeper
All readings
fast; speed
fast; quick; speed; velocity
快；快慢的程度。 — studyhanzi 编写
Words with this reading
- 速度sù dùspeed; velocity; pace速 = sù
- 迅速xùn sùrapid; swift; speedy速 = sù
- 匀速yún sùuniform speed; constant velocity速 = sù
Sound component
束 family onset shift
Stroke data: hanzi-writer-data (Arphic Public License) · licenses & attributions
Questions people ask about this character
What does 速 mean?
速 (sù) means fast; quick; speed; velocity.
How do you pronounce 速?
It is pronounced sù.
What parts is 速 made of?
辶 (walk; go — the "movement" radical (chuò)) and 束 (a bundle; to tie up), one enclosing the other. The recorded source is: 说文解字: 速，疾也。从辵束聲；IDS 拆分 ⿺辶束，并以 hanzi-writer-data 笔画核验：笔画 0–6 与「束」逐笔对应，笔画 7–9 为「辶」（点、横折折撇、平捺）. Components are the building blocks of the shape; the radical used for dictionary lookup is a separate thing.
How many strokes does 速 have?
10. You can watch the stroke order on this page, or trace it yourself.
What is the radical of 速?
辶. The radical is how the character is filed in a dictionary — it is not the whole story of how the character is built.
What words use 速?
Common ones are 速度, 迅速, 匀速. The reading of 速 is not the same in every word, so each word on this page shows which reading applies.