Attosecond is 1e-18 second units.
Attoseconds to Femtoseconds Converter — as to fs
Convert Attosecond (as) to Femtosecond (fs) using the exact conversion factor (1 attosecond = 0.001 femtosecond). See the formula, worked examples, and conversion table.
Attoseconds to Femtoseconds converter
Converter
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Context values
Some unit families need one extra value for a physically accurate result.
Femtosecond is 1e-15 second units.
Result = input x 1e-18 / 1e-15.
Months and years use the average Gregorian year.
Reserved above the conversion cards and below the converter.
About Converting Attoseconds to Femtoseconds
Attosecond and Femtosecond are both everyday units of duration, and converting between them is one of the most routine calculations there is — scheduling, project planning, and billing all depend on it. Specifically: Attosecond is 1e-18 second units, and femtosecond is 1e-15 second units.
Formula
femtoseconds = attoseconds × 0.001
This factor comes from each unit's defined relationship to the category's base unit: 1 attosecond equals 1e-18 base units, and 1 femtosecond equals 1e-15 base units, so dividing one by the other gives the direct attosecond-to-femtosecond factor of 0.001.
Simple example
1 as × 0.001 = 0.001 fs
1 attosecond = 0.001 femtoseconds.
Real-world example
24 as × 0.001 = 0.024 fs
24 attoseconds = 0.024 femtoseconds.
Conversion table
| Attosecond (as) | Femtosecond (fs) |
|---|---|
| 1 as | 0.001 fs |
| 7 as | 0.007 fs |
| 24 as | 0.024 fs |
| 30 as | 0.03 fs |
| 100 as | 0.1 fs |
| 365 as | 0.365 fs |
Reverse conversion: Femtosecond to Attosecond
0.001 fs × 1000 = 1 as
0.001 femtoseconds = 1 attosecond.
attoseconds = femtoseconds × 1000
For a page dedicated to this direction, see Femtosecond to Attosecond.
Understanding the Attosecond (as)
Attosecond is 1e-18 second units.
Understanding the Femtosecond (fs)
Femtosecond is 1e-15 second units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtoseconds are in 1 attosecond?
1 attosecond equals 0.001 femtoseconds, using the exact defined conversion factor rather than an estimate.
How do I convert attosecond to femtosecond?
Multiply the attosecond value by 0.001. The converter above does this instantly to whatever precision you set.
How do I convert femtosecond back to attosecond?
Use the reverse factor: 1 femtosecond equals 1,000 attoseconds. You can also use the swap control in the converter above to flip the direction instantly.
What is a attosecond?
Attosecond (as) is a unit of time.
What is a femtosecond?
Femtosecond (fs) is a unit of time.
Is the attosecond to femtosecond conversion exact?
Yes. Both attosecond and femtosecond are defined by fixed standards rather than physical artifacts, so the factor of 0.001 used above is exact to as many digits as you choose to display.