Yocto (y)
The SI prefix yocto (y): a factor of 10⁻²⁴, which is one septillionth (10⁻²⁴).
What is a yocto unit?
- Symbol
- y
- Quantity
- SI Prefixes
- Unit system
- SI
- Definition
- The SI prefix yocto (y): a factor of 10⁻²⁴, which is one septillionth (10⁻²⁴).
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
Used for yoctograms: a proton has a mass of about 1.67 yoctograms (1.67 × 10⁻²⁴ g).
Yocto in other si prefixes units
- 1 y = 1e-54 QQuetta
- 1 y = 1e-51 RRonna
- 1 y = 1e-48 YYotta
- 1 y = 1e-45 ZZetta
- 1 y = 1e-42 EExa
- 1 y = 1e-39 PPeta
- 1 y = 1e-36 TTera
- 1 y = 1e-33 GGiga
- 1 y = 1e-30 MMega
- 1 y = 1e-27 kKilo
- 1 y = 1e-26 hHecto
- 1 y = 1e-25 daDeca
- 1 y = 1e-23 dDeci
- 1 y = 1e-22 cCenti
- 1 y = 1e-21 mMilli
- 1 y = 1e-18 µMicro
- 1 y = 1e-15 nNano
- 1 y = 1e-12 pPico
- 1 y = 1e-9 fFemto
- 1 y = 0.000001 aAtto
- 1 y = 0.001 zZepto
- 1 y = 1000 rRonto
- 1 y = 1000000 qQuecto
- 1 y = 1e-24 ×1Base unit (no prefix)
Yocto quick reference
| Yocto | Kilo | Milli | Quetta |
|---|---|---|---|
| 1 y | = 1e-27 k | = 1e-21 m | = 1e-54 Q |
| 10 y | = 1e-26 k | = 1e-20 m | = 1e-53 Q |
| 100 y | = 1e-25 k | = 1e-19 m | = 1e-52 Q |
| 1000 y | = 1e-24 k | = 1e-18 m | = 1e-51 Q |
Where the yocto unit fits
The next smaller si prefixes unit is the ronto unit (r). 1 y = 1000 r, and 1 r = 0.001 y.
The next larger si prefixes unit is the zepto unit (z). 1 y = 0.001 z, and 1 z = 1000 y.
Frequently asked questions
- How many kilo units are in one yocto unit?
- One yocto unit = 1e-27 k (kilo units).
- How many milli units are in one yocto unit?
- One yocto unit = 1e-21 m (milli units).
- How many quetta units are in one yocto unit?
- One yocto unit = 1e-54 Q (quetta units).