How many seconds in a day?
86,400. Here is the complete time-unit conversion table — seconds, minutes, hours, days and weeks — with the exact values and the conventions behind the averaged ones.
86,400 seconds
24 hours · 1,440 minutes · exactly one day
Time units, converted
| seconds | minutes | hours | days | weeks | |
|---|---|---|---|---|---|
| 1 second | 1 | 0.017 | 0 | 0 | 0 |
| 1 minute | 60 | 1 | 0.017 | 0.001 | 0 |
| 1 hour | 3,600 | 60 | 1 | 0.042 | 0.006 |
| 1 day | 86,400 | 1,440 | 24 | 1 | 0.143 |
| 1 week | 604,800 | 10,080 | 168 | 7 | 1 |
Longer spans
| 1 month | 28–31 days (calendar) · 30 days (bank convention) · 2,592,000 seconds (30-day convention) |
|---|---|
| 1 year | 365 days = 31,536,000 seconds · 366 days = 31,622,400 seconds · averaged 365.2425 days (Gregorian rule) |
| 1 week | 7 days = 168 hours = 10,080 minutes = 604,800 seconds |
Where conventions disagree — 30-day banking months vs real calendar months, averaged years vs actual years — we show both and label them. "How long is a month" has no single right answer; it has contexts.
Common questions
How many seconds are in a day?
86,400. A day has 24 hours × 60 minutes × 60 seconds — this never changes, leap seconds aside (they add one second to a single day roughly every few years).
How many seconds in a year?
31,536,000 in a common year and 31,622,400 in a leap year. "About 31.5 million" is a fine approximation; 31,536,000 is exact for 365 days.
Why do some calculators give a different year length?
Averaging over the 4-year leap cycle gives 365.25 days; the full Gregorian rule (skip leap years on century years unless divisible by 400) gives 365.2425. Both are conventions for "average year" — a specific year is either 365 or 366 days.
Last updated 2026-11-04 · Calculations follow the full leap-year rule (including the year 2100 exception).