Seconds to Days Converter
Convert seconds to days — divide by 86,400. Results update as you type; exact factors shown.
One second is 0 days — see the exact factor, not a rounded rule of thumb.
How the seconds to days 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 |
|---|---|---|
| 3,600 s | 0.0417 d | seconds to days |
| 43,200 s | 0.5 d | seconds to days |
| 86,400 s | 1 d | seconds to days |
| 172,800 s | 2 d | seconds to days |
| 604,800 s | 7 d | seconds to days |
| 1,000,000 s | 11.5741 d | seconds to days |
| 2,592,000 s | 30 d | seconds to days |
| 5,184,000 s | 60 d | seconds to days |
| 10,000,000 s | 115.7407 d | seconds to days |
| 31,536,000 s | 365 d | seconds to days |
| 100,000,000 s | 1,157.4074 d | seconds to days |
| 1,000,000,000 s | 11,574.0741 d | seconds to days |
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 million seconds in days?
11.57 days.
What is a billion seconds?
About 11,574 days — just under 31.7 years.
How do I convert seconds to days?
Divide by 86,400, which is 60 x 60 x 24.
Do leap seconds affect this?
A leap second makes one real day 86,401 seconds long, but it is far too rare to matter in a conversion.
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.