Days to Seconds Converter
Convert days to seconds — 86,400 seconds to the day. Results update as you type; exact factors shown.
One day is 86,400 seconds — see the exact factor, not a rounded rule of thumb.
How the days to seconds converter works
Time converts through the second. Minutes, hours, days and weeks are exact multiples. A month is taken as the Gregorian average (30.436875 days) and a year as the Gregorian average (365.2425 days = 31,556,952 s); calendar months and leap years vary from these averages.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common time conversions
| From | To | Units |
|---|---|---|
| 0.5 d | 43,200 s | days to seconds |
| 1 d | 86,400 s | day to seconds |
| 2 d | 172,800 s | days to seconds |
| 3 d | 259,200 s | days to seconds |
| 7 d | 604,800 s | days to seconds |
| 14 d | 1,209,600 s | days to seconds |
| 30 d | 2,592,000 s | days to seconds |
| 60 d | 5,184,000 s | days to seconds |
| 90 d | 7,776,000 s | days to seconds |
| 180 d | 15,552,000 s | days to seconds |
| 365 d | 31,536,000 s | days to seconds |
| 1,000 d | 86,400,000 s | days to seconds |
Units in this converter and their exact factors
| Unit | Symbol | One unit in seconds |
|---|---|---|
| millisecond | ms | 0.001 second |
| second | s | 1 second |
| minute | min | 60 second |
| hour | h | 3,600 second |
| day | d | 86,400 second |
| week | wk | 604,800 second |
| month (average, 30.4369 days) | mo | 2,629,746 second |
| year (365.2425 days) | yr | 31,556,952 second |
FAQFrequently asked questions about time conversion
How many seconds in a day?
Exactly 86,400.
What is a week in seconds?
604,800.
What is a year in seconds?
About 31.56 million.
Do leap seconds change this?
A leap second makes one real day 86,401 seconds long, but they are far too rare to matter here.
What is 30 days in seconds?
2,592,000.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.