Zepto (z)
The SI prefix zepto (z): a factor of 10⁻²¹, which is one sextillionth (10⁻²¹).
What is a zepto unit?
- Symbol
- z
- Quantity
- SI Prefixes
- Unit system
- SI
- Definition
- The SI prefix zepto (z): a factor of 10⁻²¹, which is one sextillionth (10⁻²¹).
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
Used for zeptoseconds. In 2020 physicists measured the time light takes to cross a hydrogen molecule as about 247 zeptoseconds.
Zepto in other si prefixes units
- 1 z = 1e-51 QQuetta
- 1 z = 1e-48 RRonna
- 1 z = 1e-45 YYotta
- 1 z = 1e-42 ZZetta
- 1 z = 1e-39 EExa
- 1 z = 1e-36 PPeta
- 1 z = 1e-33 TTera
- 1 z = 1e-30 GGiga
- 1 z = 1e-27 MMega
- 1 z = 1e-24 kKilo
- 1 z = 1e-23 hHecto
- 1 z = 1e-22 daDeca
- 1 z = 1e-20 dDeci
- 1 z = 1e-19 cCenti
- 1 z = 1e-18 mMilli
- 1 z = 1e-15 µMicro
- 1 z = 1e-12 nNano
- 1 z = 1e-9 pPico
- 1 z = 0.000001 fFemto
- 1 z = 0.001 aAtto
- 1 z = 1000 yYocto
- 1 z = 1000000 rRonto
- 1 z = 1000000000 qQuecto
- 1 z = 1e-21 ×1Base unit (no prefix)
Zepto quick reference
| Zepto | Kilo | Milli | Quetta |
|---|---|---|---|
| 1 z | = 1e-24 k | = 1e-18 m | = 1e-51 Q |
| 10 z | = 1e-23 k | = 1e-17 m | = 1e-50 Q |
| 100 z | = 1e-22 k | = 1e-16 m | = 1e-49 Q |
| 1000 z | = 1e-21 k | = 1e-15 m | = 1e-48 Q |
Where the zepto unit fits
The next smaller si prefixes unit is the yocto unit (y). 1 z = 1000 y, and 1 y = 0.001 z.
The next larger si prefixes unit is the atto unit (a). 1 z = 0.001 a, and 1 a = 1000 z.
Frequently asked questions
- How many kilo units are in one zepto unit?
- One zepto unit = 1e-24 k (kilo units).
- How many milli units are in one zepto unit?
- One zepto unit = 1e-18 m (milli units).
- How many quetta units are in one zepto unit?
- One zepto unit = 1e-51 Q (quetta units).