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Attojoule to Joule (aJ to J) Converter & Formula

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Live Conversion • ISO 80000-5:2019 Certified
1 Attojoule = 1 × 10⁻¹⁸ Joule
1 aJ = 1 × 10⁻¹⁸ J • 1 J = 1 × 10¹⁸ aJ
Attojoule to Joule: One Attojoule is equal to 1 × 10⁻¹⁸ Joules.
Certified Authority Value
0.00000000
J
Exact: 1 J ≡ 1 × 10¹⁸ aJ
aJ
aJ
J
J 1 × 10⁻¹⁸
Conversion Formula
To convert Attojoule to Joule, multiply by 1 × 10⁻¹⁸
aJ × 1 × 10⁻¹⁸ = J

Calculation: 1 aJ × 1 × 10⁻¹⁸ = 1 × 10⁻¹⁸ J

Common Attojoule to Joule Calculations

Quick-lookup reference table showing calculated equivalents for standard increments between Attojoule (aJ) and Joule (J).

Tap any row to calculate
Joule to Attojoule: Reciprocal Summary
Joule to Attojoule Conversion Reference Table
Reciprocal & Equivalent Value Scientific Notation
1 J is equal to 1 × 10¹⁸ aJ (Attojoule) 1 × 10¹⁸
5 J is equal to 5 × 10¹⁸ aJ (Attojoule) 5 × 10¹⁸
10 J is equal to 1 × 10¹⁹ aJ (Attojoule) 1 × 10¹⁹
50 J is equal to 5 × 10¹⁹ aJ (Attojoule) 5 × 10¹⁹
100 J is equal to 1 × 10²⁰ aJ (Attojoule) 1 × 10²⁰

Real-World Context & Everyday Benchmarks

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To help contextualize these units in everyday life, science, and engineering, here are verified real-world reference points for Attojoule (aJ) and Joule (J):

Attojoule References:

  • Theoretical minimum switching energy required to toggle a magnetic nanoscopic memory bit 1 aJ

Joule References:

  • Mechanical work required to lift a medium culinary apple vertically by one meter 1 J
  • Kinetic energy of a standard tennis ball dropped from waist height 1 J
  • Energy consumed by a 1-watt LED pilot lamp operating for one second 1 J
ISQ Dimension: [M L² T⁻²] Coherent SI Unit: joule (J) Chemical Engineering, Solutions & Physical Chemistry

How to Convert Attojoule to Joule

Converting Attojoule (aJ) to Joule (J) is a core calculation in Energy and Work, which quantifies the physical capacity to perform mechanical work, generate heat, or emit electromagnetic radiation. Both units reside within the International System of Units (SI) and share an identical physical dimension vector ([M L² T⁻²]), separated strictly by a decimal order-of-magnitude factor (10^-18). Because this shift involves integer powers of 10, the conversion is mathematically exact and free from decimal rounding or irrational fractional loss. Exactly 1 Attojoule equals 1 × 10⁻¹⁸ Joule.

Direct Factor1 aJ = 1 × 10⁻¹⁸ J
Inverse Ratio1 J = 1 × 10¹⁸ aJ
Conversion ScalePure SI Metric Prefix Shift (10ⁿ Decimal Scaling)
First-Principles SI Derivation ProofNIST SP 811 / ISO 80000 Compliance

Mathematical Conversion Derivation via Coherent SI Base Unit

Under the International System of Quantities (ISQ), dimensional conversion between non-SI units is rigorously resolved by bridging through the coherent SI base unit (joule (J)) without arbitrary rounding:

Vtarget=Vsource×(ksource→SIktarget→SI)V_{\text{target}} = V_{\text{source}} \times \left( \frac{k_{\text{source} \to \text{SI}}}{k_{\text{target} \to \text{SI}}} \right)
Universal Dimensional Conversion Law (ISO 80000 / NIST SP 811)
1. Source SI Bridge (ksource):1 aJ = 1 × 10⁻¹⁸ joule (J)
2. Target SI Bridge (ktarget):1 J = 1 joule (J)
Step-by-step substitution for Attojoule → Joule:V(J) = V(aJ) × ( 1 × 10⁻¹⁸ / 1 ) = V(aJ) × 1 × 10⁻¹⁸
Mathematical FormulaValue in Joule = Value in Attojoule × 1 × 10⁻¹⁸Direct computational formula applied for standard conversion.
Worked Example

For an engineering input of 36 aJ, applying the conversion factor yields exactly 3.6 × 10⁻¹⁷ J. At larger operational scale, 1000 Attojoule corresponds to 1 × 10⁻¹⁵ J.

Inverse check: 1 J = 1 × 10¹⁸ aJ.

Understanding Attojoule and Joule

Attojoule

aJ
SI Submultiple

An Attojoule (aJ) is a decimal submultiple of the SI-derived unit for energy and work.

Applications & Practical Context

In practical energy terms, a theoretical minimum switching energy required to toggle a magnetic nanoscopic memory bit equals 1 aJ.

Physical Setup

An energy quantity of 1 aJ corresponds to 1 × 10⁻¹⁸ J (performing 1 × 10⁻¹⁸ joules of work or heat transfer).

Conversion to SI Unit: joule (J)
1 aJ = 1 × 10⁻¹⁸ J

Joule

J
Coherent SI Unit

The joule (J) is the coherent SI-derived unit of energy, work, and heat, named after James Prescott Joule.

Applications & Practical Context

In practical energy terms, a mechanical work required to lift a medium culinary apple vertically by one meter equals 1 J, a kinetic energy of a standard tennis ball dropped from waist height equals 1 J, a energy consumed by a 1-watt LED pilot lamp operating for one second equals 1 J.

Physical Setup

An energy of 1 joule is the work done by a force of 1 newton acting through a displacement of 1 meter, or dissipating 1 watt of electrical power over 1 second.

Conversion to SI Unit: joule (J)
1 J = 1 N·m = 1 W·s

Domain Metrology & Engineering Applications

Governing Law & Equation

First Law of Thermodynamics (Conservation of Energy: ΔU = Q - W)

Measurement Instrumentation

Rigorously quantified in laboratory and field settings using isoperibol bomb calorimeters, optical laser pulse joulemeters, and digital revenue-grade electric energy meters.

Primary Industry Sectors

Applied across electric power utility metering, thermal energy storage design, chemical plant process enthalpies, and ballistic impact engineering under international metrology standard ISO 80000-5:2019, NIST SP 811.

Physical Orders of Magnitude & Laboratory Reference Benchmarks

Physical Phenomenon / Engineering ReferenceReference ValueConverted to Joule
Theoretical minimum switching energy required to toggle a magnetic nanoscopic memory bit1 aJ1 × 10⁻¹⁸ J
Institutional Metrology & Standard Authority:

Formulas, conversion coefficients, and base definitions on this page strictly adhere to the ISO 80000-5:2019, NIST SP 811 and the BIPM SI Brochure (9th Edition). Governed by First Law of Thermodynamics (Conservation of Energy: ΔU = Q - W) under ISO 80000 dimensional vector [M L² T⁻²].

Multi-Variable Engineering Bridge Grid Energy & Industrial Work

Continuous Power & Operating Duration Bridge (kWh • Megajoules • BTU • Average Power • Battery Runtime)

Bridge instantaneous work rate [M L² T⁻³] and accumulated energy consumption [M L² T⁻²] over operational shifts and duty cycles via the work-power equation E = P × t.

E = P × t
Live Calculated Bridge Equivalent:
1 aJ at 1-Hour Standard Benchmark Runtime = 1 × 10⁻²¹ kWh
Equals 3.6 × 10⁻²¹ MJ • 3.41 × 10⁻¹⁸ BTU • 3.6 × 10⁻¹⁵ J
Utility Standard
1 × 10⁻²¹
kWh
Kilowatt-Hours
SI Metric Energy
3.6 × 10⁻²¹
MJ
Megajoules
HVAC & Thermal
3.41 × 10⁻¹⁸
BTU
British Thermal Units
SI Base Unit
3.6 × 10⁻¹⁵
J
Joules
Grid Power Scale
1 × 10⁻²⁴
MWh
Megawatt-Hours
Mechanical Work
1.341 × 10⁻²¹
hp·h
Horsepower-Hours
  1. 1. Normalize Input to SI Base Unit (W):
    P = 1 aJ × 1 × 10⁻¹⁸ = 1 × 10⁻¹⁸ W
  2. 2. Apply Engineering Parameter (t):
    Selected condition: 1-Hour Standard Benchmark Runtime at t = 3600 Seconds / Hours
  3. 3. Execute Governing Physical Law in SI Units:
    E = P × t = (1 × 10⁻¹⁸) × (3600) = 3.6 × 10⁻¹⁵ J
  4. 4. Convert to Standard Engineering Units:
    • kWh: 3.6 × 10⁻¹⁵ × 2.7778 × 10⁻⁷ = 1 × 10⁻²¹ kWh (Kilowatt-Hours) • MJ: 3.6 × 10⁻¹⁵ × 1 × 10⁻⁶ = 3.6 × 10⁻²¹ MJ (Megajoules) • BTU: 3.6 × 10⁻¹⁵ × 0.0009478 = 3.41 × 10⁻¹⁸ BTU (British Thermal Units) • J: 3.6 × 10⁻¹⁵ × 1 = 3.6 × 10⁻¹⁵ J (Joules) • MWh: 3.6 × 10⁻¹⁵ × 2.7778 × 10⁻¹⁰ = 1 × 10⁻²⁴ MWh (Megawatt-Hours) • hp·h: 3.6 × 10⁻¹⁵ × 3.7251 × 10⁻⁷ = 1.341 × 10⁻²¹ hp·h (Horsepower-Hours)
Explore Full Power Converter →
Engineering Substance / Operating Standard Parameter Value (Seconds / Hours) Reference State / Condition Typical Industrial & Engineering Application
1-Second Pulse (Inrush / Circuit Breaker) 1 1.0 second Motor inrush peak & capacitor discharge
1-Minute Short Cycle (Microwave / Lift) 60 60 seconds Elevator transit & commercial appliance duty
1-Hour Standard Benchmark Runtime 3600 3,600 seconds Standard utility kilowatt-hour energy basis
8-Hour Factory Shift (Industrial Machinery) 28800 8.0 hours Single industrial production line workday
24-Hour Continuous Day (Data Center / Pump) 86400 24.0 hours Always-on server racks & municipal water treatment
7-Day Continuous Week (Chemical Refining) 604800 168.0 hours Continuous manufacturing process plant run
30-Day Monthly Billing Cycle 2592000 720.0 hours Electric utility meter billing period
365-Day Annual Base Load Operation 3.1536 × 10⁷ 8,760 hours Grid generator annual capacity factor calculation
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Frequently Asked Questions

There are exactly 1 × 10⁻¹⁸ joules (J) in 1 attojoule (aJ). To calculate larger amounts manually, simply multiply your total number of attojoules by the conversion multiplier of 1 × 10⁻¹⁸.

The mathematical formula to convert attojoules to joules is: [value] * 1 × 10⁻¹⁸ = joules. Rather than doing the math manually, you can use our high-precision online calculator to process this exact equation instantly without rounding errors.

To perform the reverse calculation from joules back to attojoules, you must divide your starting value by 1 × 10⁻¹⁸. Our bidirectional tool automatically computes this inverse equation the moment you type into the joule input field.

1 Joule is larger than 1 Attojoule. Specifically, 1 Attojoule equals 1 × 10⁻¹⁸ joules, meaning 1 Joule is 1 × 10¹⁸ times larger than 1 Attojoule (a difference of 18.00 orders of magnitude). Expressing measurements in attojoules requires a larger numerical value to represent the equivalent physical magnitude.

A typical theoretical minimum switching energy required to toggle a magnetic nanoscopic memory bit measures 1 aJ, which corresponds to 1 × 10⁻¹⁸ J (Joule).

Under ISO 80000 standards, 1 aJ = 1.00000 × 10⁻¹⁸ J.

The specific conversion formula is V(J) = V(aJ) × 1.00000 × 10⁻¹⁸.

To convert from Joules to Attojoules, use the equation V(aJ) = V(J) × 1.00000 × 10¹⁸.

Attojoules represent quantum-scale energy transfers or molecular bond energies, while the Joule serves as the standard macroscopic SI unit of energy.