Convert Pico to Atto

Pico (p) to Atto (a) SI prefix conversion — enter any value below to get an instant result, or use the table for common values.

Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.

Value

From

Result

1 p = 1000000 a

1 Pico = 1000000 Atto

1 Atto = 1E-06 Pico

1 p in every supported prefix

Conversion chart: Pico to Atto

Conversion table

Pico (p)	Atto (a)
0.01 p	10000 a
0.1 p	100000 a
1 p	1000000 a
2 p	2000000 a
3 p	3000000 a
5 p	5000000 a
10 p	10000000 a
20 p	20000000 a
50 p	50000000 a
100 p	1E+08 a
1000 p	1E+09 a

Pico (p)

Definition: An SI prefix denoting a factor of 10⁻¹² — one trillionth of the base unit.

History: Adopted by the CGPM in 1960 alongside nano-, extending the SI's small-scale prefixes as electronics and physics needed to describe ever-tinier quantities.

Current use: Common in electronics (picofarads for small capacitors) and in describing extremely short time intervals (picoseconds) in laser and telecommunications research.

Atto (a)

Definition: An SI prefix denoting a factor of 10⁻¹⁸ — one quintillionth of the base unit. From the Danish/Norwegian 'atten' (eighteen).

History: Adopted by the CGPM in 1964 alongside femto-, extending the SI down to the sub-atomic measurement scale.

Current use: Used in high-precision physics measurements, including attosecond-scale laser pulses used to study electron motion within atoms.

Supported Units

Prefix	Symbol	Multiplier (× base)
Yotta	Y	1E+24
Zetta	Z	1E+21
Exa	E	1E+18
Peta	P	1E+15
Tera	T	1E+12
Giga	G	1E+09
Mega	M	1000000
Kilo	k	1000
Hecto	h	100
Deka	da	10
None (base unit)	—	1
Deci	d	0.1
Centi	c	0.01
Milli	m	0.001
Micro	µ	1E-06
Nano	n	1E-09
Pico	p	1E-12
Femto	f	1E-15
Atto	a	1E-18
Zepto	z	1E-21
Yocto	y	1E-24

About These Parameters

Value: The number of "From" prefix units you want to re-express in the "To" prefix. Since prefixes are just multiplier scales, this value can represent anything from a physical quantity's leading digits to a plain abstract number.
From Unit: The SI prefix your value is currently scaled by — for example, the "kilo" in "kilogram" or the "nano" in "nanosecond," entered here without the base unit attached.
To Unit: The SI prefix you want the value re-expressed in. Use the swap button to flip From and To instantly, handy when converting a datasheet figure from one prefix scale to another.

How Prefix Conversion Works

The Formula

Every SI prefix is defined by a fixed power-of-ten multiplier relative to the unprefixed base value. To convert a value from one prefix scale to another:

result = value × (multiplier of "From" prefix ÷ multiplier of "To" prefix)

For Pico → Atto: multiply by 1000000. For example, 1 p × 1000000 = 1000000 a.

A History of Powers of Ten

The original six metric prefixes — kilo, hecto, deka, deci, centi, milli — were adopted by the French Academy of Sciences in 1795 alongside the metric system itself. As science and industry needed to describe ever-larger and ever-smaller quantities, the CGPM (Conférence Générale des Poids et Mesures) extended the table repeatedly: mega and micro in 1960 when the modern SI was formalized, giga and nano the same year, tera and pico following soon after, then peta/femto (1975), exa/atto (1975), and finally zetta/zepto and yotta/yocto in 1991 — the classical range covered on this page. In 2022 the CGPM went further still, adding ronna/ronto and quetta/quecto to keep pace with data-storage and astrophysical quantities that had begun to outgrow even yotta.

Why a Prefix-Only Converter Is Useful

Every other unit converter on this site attaches these same prefixes to one specific base unit — grams, watts, bytes, farads — because that's how the prefix is actually used in practice. But the underlying math of "how much bigger is giga than mega" never changes no matter which unit it's modifying, so it's often faster to reason about the prefix scale on its own: quickly checking that a "giga" figure is a billion and not a million, or converting a "nano" measurement from one datasheet into the "micro" scale used by a different one, without needing to know or care what physical quantity either figure describes.

Example

1 p equals 1000000 a. Whatever base unit these prefixes are actually attached to — grams, bytes, watts, seconds — the same multiplier ratio applies: 1 kilo- is always 1,000 times 1 (unprefixed), and 1 mega- is always 1,000 times 1 kilo-, regardless of the quantity being measured.

Frequently Asked Questions

How many Atto are in 1 Pico?

1 Pico (p) equals exactly 1000000 Atto (a).

Is giga a billion or a million?

Giga is always a billion (10⁹) times the base unit — a common point of confusion is with "mega," which is a million (10⁶). The two are frequently mixed up in casual conversation about data storage and computing speed, which is exactly the kind of mistake this converter is designed to catch.

Does this converter work for any unit, like grams or bytes?

Yes — this converter deliberately ignores the underlying unit and works purely with the multiplier scale. "1 kilo- to mega-" gives the same ratio (0.001) whether you mentally attach it to grams, watts, bytes, or any other quantity, because the prefix's multiplier is independent of what it's modifying.

What does "None (base unit)" mean in the unit list?

"None (base unit)" represents a value with no prefix attached at all — a plain gram, meter, or watt rather than a kilogram, kilometer, or milliwatt. It's included so you can convert directly between an unprefixed value and any prefixed scale, such as figuring out how many kilo- units equal one plain (unprefixed) unit.

Are ronna, ronto, quetta, and quecto included here?

Not yet — this page covers the classical SI prefix range from yotta (10²⁴) down to yocto (10⁻²⁴), which was complete from 1991 until 2022. The newer 2022 additions (ronna/ronna-, quetta/quecto) sit beyond even yotta and yocto and aren't included in this table.

Convert Pico to Other Prefixes

Possible Prefix Conversions

Hecto to Deci Giga to Hecto Micro to Deka Atto to None (base unit) Deka to Hecto Kilo to Micro Exa to Giga Micro to Kilo None (base unit) to Kilo Tera to Nano Nano to Deka Tera to Deci Pico to Tera Exa to Hecto Exa to Yocto Zepto to Exa Hecto to Peta Yotta to Femto Centi to Nano Deka to Mega Centi to Yocto Pico to Milli Giga to Exa None (base unit) to Zepto Deka to Zepto Kilo to Nano Hecto to Centi Tera to Peta Mega to Tera Zetta to Deci Yotta to Deci None (base unit) to Yotta Hecto to Deka Giga to Yocto Kilo to None (base unit) Kilo to Hecto Micro to Deci Pico to Centi Centi to Milli Exa to Centi Peta to Yocto Atto to Exa Exa to Peta Kilo to Milli Yotta to Hecto Zepto to Micro Hecto to Yotta Deka to Atto Micro to Giga Kilo to Deka Atto to Mega Deci to Zepto Pico to Atto None (base unit) to Pico None (base unit) to Exa Centi to None (base unit) Tera to Zetta Femto to Kilo Pico to Nano Yotta to Pico Hecto to Pico Peta to None (base unit) Atto to Hecto Deci to Mega Centi to Exa Giga to Femto Zepto to Tera Femto to Exa None (base unit) to Atto Milli to Giga Yocto to Peta Milli to Zetta Micro to Yocto Centi to Micro Peta to Pico Micro to Atto Deka to Milli Yocto to Hecto Zepto to Hecto Deci to Pico Femto to Atto Atto to Zetta None (base unit) to Deka Micro to Peta Femto to Yocto Deka to Exa Centi to Atto Mega to Peta Tera to Giga Micro to Milli Kilo to Yotta Mega to None (base unit) Yocto to Kilo Nano to Atto Mega to Deka Zetta to Giga Atto to Femto Milli to Yocto Milli to Yotta Nano to Giga Nano to Mega Nano to Femto Femto to Tera Deci to Deka Zetta to None (base unit) Micro to Zepto Nano to Exa Deka to Tera Zetta to Zepto Centi to Yotta Nano to Hecto Milli to Zepto Tera to Zepto Deci to Peta Pico to Peta None (base unit) to Mega Micro to Centi Kilo to Deci None (base unit) to Zetta Zetta to Kilo Deka to Zetta Yotta to Tera Micro to Nano Yotta to Kilo Peta to Milli Zepto to Mega Micro to Hecto Deci to Zetta Yocto to Zepto Nano to Tera Exa to Zepto Giga to Deka Atto to Yotta Milli to Nano Hecto to Zepto Atto to Kilo Femto to Zetta Milli to None (base unit) Tera to Exa None (base unit) to Femto Exa to Deci Giga to Peta Hecto to Yocto Yocto to Atto Zetta to Mega Peta to Micro Nano to Zetta Yocto to Exa Nano to Zepto Nano to Milli Pico to Deci Pico to Mega Deka to Kilo Micro to Exa Deci to None (base unit) Deka to None (base unit) Kilo to Zepto Zepto to Atto Deci to Atto Tera to None (base unit) Hecto to Femto Atto to Micro Pico to None (base unit) Kilo to Giga Micro to Tera Femto to Centi Yotta to Giga Yotta to None (base unit) Tera to Centi Femto to Mega Deci to Yotta Deka to Yotta Pico to Exa Giga to Yotta Femto to Nano Yocto to Deci Pico to Yocto Yotta to Peta Nano to Deci Deka to Nano Yocto to Milli Nano to Micro Mega to Milli Pico to Hecto Mega to Kilo Yocto to Pico None (base unit) to Yocto Zepto to Giga Centi to Hecto Deci to Exa Centi to Femto None (base unit) to Micro Exa to Kilo Mega to Exa Exa to Deka Exa to Atto Femto to Peta Yotta to Zetta Deci to Milli Kilo to Exa Femto to Deci Centi to Peta Milli to Exa Mega to Zetta Atto to Zepto Deka to Femto Tera to Yocto Atto to Peta Mega to Giga Peta to Nano Nano to Yocto Exa to Mega Centi to Tera Peta to Zetta Mega to Hecto Zepto to Milli Pico to Femto Centi to Zepto Peta to Zepto Tera to Kilo Giga to Centi Yotta to Centi Yocto to Centi Giga to Atto Atto to Nano Hecto to None (base unit) Mega to Atto Zepto to Nano None (base unit) to Deci Exa to Micro Tera to Deka Peta to Mega Tera to Milli Yocto to Tera Tera to Micro Kilo to Femto Giga to Micro Femto to Giga Micro to Zetta Giga to None (base unit) Atto to Milli Zepto to Yotta Peta to Deci Mega to Femto Milli to Pico Tera to Yotta Pico to Kilo None (base unit) to Giga Centi to Mega Yotta to Micro Yotta to Milli Giga to Pico Pico to Yotta Zetta to Yotta Deci to Yocto Mega to Yotta Femto to Deka Deci to Tera Nano to Peta None (base unit) to Centi Mega to Pico Zepto to Deci Deka to Deci Centi to Deci Peta to Yotta Kilo to Pico Yocto to Giga Zepto to Zetta Milli to Femto Hecto to Tera Exa to None (base unit) Peta to Kilo Mega to Nano Exa to Tera None (base unit) to Milli Milli to Centi Yotta to Nano Yocto to Micro Deka to Pico Deci to Nano Giga to Nano Zetta to Exa Milli to Peta Milli to Hecto Yocto to None (base unit) Peta to Deka Giga to Tera Zetta to Femto Peta to Hecto Zetta to Hecto Zetta to Yocto Exa to Femto Zetta to Deka Atto to Deci Yotta to Yocto Hecto to Mega Mega to Centi Deci to Kilo Hecto to Giga Centi to Deka Nano to Yotta Peta to Tera None (base unit) to Peta Pico to Zepto Milli to Mega Kilo to Atto Pico to Giga Femto to Milli Nano to Pico Centi to Giga Peta to Exa Mega to Zepto Atto to Tera Centi to Zetta Milli to Kilo Kilo to Tera Pico to Micro Deci to Hecto Zepto to Femto Zepto to Centi Micro to None (base unit) Yocto to Yotta Zetta to Atto Giga to Zepto Femto to None (base unit) Nano to None (base unit) Pico to Deka Femto to Micro Hecto to Exa Milli to Atto Yocto to Zetta Zepto to Kilo Deci to Micro Micro to Mega Milli to Deci Giga to Deci Atto to Yocto Deci to Centi Hecto to Micro Zetta to Milli Yotta to Exa Yocto to Deka Deka to Peta Tera to Hecto Zetta to Micro Atto to Centi Tera to Mega Centi to Pico Micro to Femto Mega to Deci Yotta to Zepto Hecto to Kilo Hecto to Atto Yotta to Atto Mega to Yocto Micro to Yotta Milli to Tera Zepto to Deka Femto to Zepto Yocto to Nano Deka to Centi Hecto to Zetta Zepto to Pico Nano to Centi Giga to Mega Peta to Giga Kilo to Centi Atto to Pico None (base unit) to Hecto Milli to Micro Tera to Pico Peta to Atto Peta to Femto Giga to Kilo None (base unit) to Nano Deci to Giga Deka to Micro Kilo to Peta Deci to Femto Yocto to Femto Femto to Pico Atto to Deka Exa to Pico Peta to Centi Atto to Giga Pico to Zetta Femto to Yotta Nano to Kilo Zepto to None (base unit) Zetta to Peta Zetta to Nano Exa to Nano Yotta to Mega Exa to Milli Giga to Zetta Zetta to Pico Deka to Giga Tera to Femto Milli to Deka Kilo to Zetta Yotta to Deka Kilo to Yocto Zepto to Peta Hecto to Nano Giga to Milli Zetta to Centi Centi to Kilo Deka to Yocto None (base unit) to Tera Tera to Atto Zetta to Tera Exa to Yotta Exa to Zetta Mega to Micro Kilo to Mega Yocto to Mega Zepto to Yocto Hecto to Milli Micro to Pico Femto to Hecto