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

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