Days to Seconds Converter
Enter the time in days below to convert it to seconds.
Convert Days to Seconds
Enter a value in days (d) to convert to seconds (s).
Day to Second Conversion Table
Table showing various day measurements converted to seconds. Click any preset value or arrow to load it into the converter.
| Days (d) | Seconds (s) |
|---|---|
| 0.5 d | 43,200 s |
| 1 d | 86,400 s |
| 2 d | 172,800 s |
| 5 d | 432,000 s |
| 10 d | 864,000 s |
| 15 d | 1,296,000 s |
| 20 d | 1,728,000 s |
| 25 d | 2,160,000 s |
| 30 d | 2,592,000 s |
| 50 d | 4,320,000 s |
How to Convert Days to Seconds
To convert days to seconds, multiply the time by the following conversion ratio: 86,400 seconds/day.
Since one day is equal to 86,400 seconds, you can use this simple formula to convert:
The time in seconds is equal to the time in days multiplied by 86,400.
For example, here's how to convert 1 days to seconds using the formula above.
How Many Seconds Are in a Day?
There are 86,400 seconds in a day, which is why we use this value in the formula above.
Our day to second calculator automatically converts your time measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Days and seconds are both units used to measure time. Keep reading to learn more about each unit.
What Is a Day?
A day is a unit of time equal to 86,400 seconds (s), the base unit for time. Civil day equal to 24 hours or 86,400 seconds. [1]
The day is classified as a standard unit of time. Days can be abbreviated as d; for example, 1 day can be written as 1 d.
When working with days (d) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, days (d) are widely used across large-scale industrial, bulk, and macro-level time specifications within international standard 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 days (d) and seconds (s), keep full floating-point precision (1 d = 86,400 s; 1 s = 0.000011574 d) during intermediate calculations and round only the final second figure to match your instrument tolerance.
More Day & Second Conversions
Need to calculate in the opposite direction? Use our seconds to days converter (s to d) to switch your starting unit immediately. You can also explore related tools such as converting milliseconds to seconds, converting minutes to seconds, or converting days to hours.
Frequently Asked Questions
References
- [1]NIST OWM StandardNIST OWM (SI Units — Time)·Time Metrology Standard — Days (d) to Seconds (s)
- [2]BIPM SpecificationBIPM (SI Base Unit: Second (s))·Unit Specifications: Day (d) & Second (s)
- [3]NIST CUU ReferenceNIST CUU (Non-SI Units Accepted for Use (min, h, d))·Conversion Factors & Mathematical Basis (d to s)