Days to Seconds (d to s) Converter and Formula
1 day equals 86,400 seconds — multiply the number of days by 86400 to convert. A day is 24 hours, each hour is 3,600 seconds, so 24 × 3600 = 86,400 seconds. The factor is exact, which is why 86400 shows up everywhere from Unix timestamps to cron schedules.
The formula
To convert days to seconds, multiply by 86400:
seconds = days × 86400
Example: 2 × 86400 = 172800 secondsTo reverse it, divide seconds by 86400 (or multiply by 1.157407e-5) to get days.
Conversion table
| Days | Seconds |
|---|---|
| 1 | 86,400 |
| 2 | 172,800 |
| 3 | 259,200 |
| 5 | 432,000 |
| 10 | 864,000 |
| 25 | 2,160,000 |
| 50 | 4,320,000 |
| 100 | 8,640,000 |
| 500 | 43,200,000 |
| 1000 | 86,400,000 |
How to convert online
- Type the number of days into the first box.
- Read the seconds value instantly in the second box.
- Or enter a second value to convert back to days — it works both ways.
Use the Day to Second Converter — free and instant in your browser.
Where this conversion is used
Days-to-seconds conversion is essential in programming, where timeouts, cache TTLs, token lifetimes and cron intervals are set in seconds. It also appears in physics and engineering calculations, uptime and reliability metrics, and anywhere a multi-day duration needs to be expressed as a single, precise second count.
FAQ
How many seconds are in a day?
One day equals 86,400 seconds. Multiply days by 86400 — for example, 10 days = 864,000 seconds.
What is the formula to convert days to seconds?
seconds = days × 86400. The converter applies this exact factor automatically.
How do I convert seconds back to days?
Divide by 86400. For example, 172,800 seconds ÷ 86400 = 2 days.
Is the conversion exact?
Yes. A standard day is defined as exactly 86,400 seconds, so there is no rounding.
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