Femtoseconds to Seconds Converter
Enter the time in femtoseconds below to convert it to seconds.
Convert Femtoseconds to Seconds
Enter a value in femtoseconds (fs) to convert to seconds (s).
Femtosecond to Second Conversion Table
Table showing various femtosecond measurements converted to seconds. Click any preset value or arrow to load it into the converter.
| Femtoseconds (fs) | Seconds (s) |
|---|---|
| 1 fs | 1e-15 s |
| 10 fs | 1e-14 s |
| 100 fs | 1e-13 s |
| 1,000 fs | 1e-12 s |
| 10,000 fs | 1e-11 s |
| 100,000 fs | 1e-10 s |
| 1,000,000 fs | 1e-9 s |
| 5,000,000 fs | 5e-9 s |
| 10,000,000 fs | 0.00000001 s |
| 25,400,000 fs | 0.000000025 s |
How to Convert Femtoseconds to Seconds
To convert femtoseconds to seconds, multiply the time by the following conversion ratio: 1e-15 seconds/femtosecond.
Since one femtosecond is equal to 1e-15 seconds, you can use this simple formula to convert:
The time in seconds is equal to the time in femtoseconds multiplied by 1e-15.
For example, here's how to convert 5 femtoseconds to seconds using the formula above.
How Many Seconds Are in a Femtosecond?
There are 1e-15 seconds in a femtosecond, which is why we use this value in the formula above.
Our femtosecond to second calculator automatically converts your time measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Femtoseconds and seconds are both units used to measure time. Keep reading to learn more about each unit.
What Is a Femtosecond?
A femtosecond is a unit of time equal to 1e-15 seconds (s), the base unit for time. One-quadrillionth of a second (10⁻¹⁵ s), used in ultrafast laser physics. [1]
The femtosecond is classified as a metric and SI-compatible unit of time. Femtoseconds can be abbreviated as fs; for example, 1 femtosecond can be written as 1 fs.
In the metric system, "femto" is the standard SI prefix for quadrillionths, or 10⁻¹⁵. This makes the femtosecond (fs) a convenient decimal multiple of the second (s).
In practice, femtoseconds (fs) are widely used across fine-tolerance laboratory, analytical, and micro-scale time measurements within SI metric workflows, engineering documentation, and technical data sheets.
What Is a Second?
Base SI unit of time. It serves as a primary reference unit for measuring time across scientific and practical applications. [2]
The second is classified as an International System of Units (SI) unit of time. Seconds can be abbreviated as s; for example, 1 second can be written as 1 s.
As the primary coherent reference unit for time in this category, all other time units are mathematically anchored to the second (s).
In practice, seconds (s) are widely used across standard time applications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.
When converting time between femtoseconds (fs) and seconds (s), keep full floating-point precision (1 fs = 1e-15 s; 1 s = 1e+15 fs) during intermediate calculations and round only the final second figure to match your instrument tolerance.
More Femtosecond & Second Conversions
Need to calculate in the opposite direction? Use our seconds to femtoseconds calculator to switch your starting unit immediately. You can also explore related tools such as converting seconds to femtoseconds, converting milliseconds to seconds, or converting days to seconds.
Convert from Femtoseconds
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Time)·Time Metrology Standard — Femtoseconds (fs) to Seconds (s)
- [2]BIPM SpecificationBIPM (SI Base Unit: Second (s))·Unit Specifications: Femtosecond (fs) & Second (s)
- [3]NIST CUU ReferenceNIST CUU (Non-SI Units Accepted for Use (min, h, d))·Conversion Factors & Mathematical Basis (fs to s)