hectojoule to attojoule
Convert hectojoule (hJ) to attojoule (aJ). Use an editable energy converter, conversion formula, and reference table.
1 hJ = 1e+20 aJ
Conversion formula
One hectojoule equals 1e+20 attojoule. Multiply your value in hectojoule by this factor to get attojoule. For the reverse conversion, divide by the same factor.
Worked example
To convert 5 hectojoule:5 × 1e+20 = 5e+20 aJ
Conversion table
| hectojoule (hJ) | attojoule (aJ) |
|---|---|
| 0.01 | 1e+18 |
| 0.1 | 1e+19 |
| 1 | 1e+20 |
| 2 | 2e+20 |
| 5 | 5e+20 |
| 10 | 1e+21 |
| 25 | 2.5e+21 |
| 50 | 5e+21 |
| 100 | 1e+22 |
| 1000 | 1e+23 |
About these measurements
Energy can be transferred through work, heating, or electrical processes.
The base reference used here is the joule. One hectojoule is 100 base units; one attojoule is 1e-18 base units.
Important distinctions
Calorie and BTU definitions vary. These pages label thermochemical calories and International Table BTUs explicitly.
Precision
The converter uses stored conversion factors and floating-point arithmetic. Results display up to ten significant digits, switching to scientific notation for very small or large values. Keep the precision of your original measurement when reporting results.
Common questions
How do I convert hJ to aJ?
Multiply the quantity in hJ by 1e+20. You can also type the value into the converter above.
Can I reverse the conversion?
Yes. Use the swap button or open the attojoule to hectojoule converter.
Reference
NIST Guide to the SI — conversion factors and prefix conventions. SI prefixes scale units by powers of ten; the dimension-specific notes above describe the assumptions used on this page.
