**Ever Wondered How Many Seconds In A Day? How about a week? A year? Thanks to Rent, we might know the number of minutes in a year (525,600), but how many seconds is that?**

Whether you’re trying to get even more granular about how you measure a year or you’re just trying to figure out how many seconds are left until summer vacation, **this guide will teach you how many seconds are in a day, a week, a year, and beyond.** Not only will we teach you how to calculate these problems, but we’ll also give you a handy chart to keep track of them.

Read on to find out how to swap one unit of time for another!

## Seconds in a day calculation How Many Seconds In A Day

One day has 24 hours, one hour has 60 minutes and one minute has 60 seconds, so 24 hours/day times 60 minutes/hour times 60 seconds/minute is equal to 86400 seconds/day:

1 day = 24 hours/day × 60 minutes/hour × 60 seconds/minute = 86400 seconds/day

## How many seconds are in a 24 hour day?

**Second and hour are units to measure time.**

## Answer: 24 hours = 86400 seconds

Let’s convert 24 hours into seconds.

**Explanation: how many seconds in an hour**

We know that,

1 day = 24 hours

In 1 hour there are 60 minutes and in 1 minute there are 60 seconds.

Therefore number of seconds in 1 hour = 60 × 60 = 3600 seconds

Now, number of seconds in 24 hours or in a day = 24 × 3600 = 86400 seconds

### Thus, there are 86400 seconds in 24 hours or in a day.

## What’s a Second?

Before we get into how many seconds there are in a day, let’s talk about what a second is. **A second is our base unit of time**—base, but not smallest. **A base unit is a unit defined on its own terms upon which other units are based.** That means that all our other units, such as minutes, hours, nanoseconds, and so on, are all based on seconds. We talk about hours in terms of minutes, but minutes are based on seconds, bringing us back to the base unit.

**A second used to be based on the Earth’s rotation cycle, with one second being 1/86,400 of the average solar day.** Now that we know more about how the Earth rotates—and that the speed at which it rotates is slowing down—we now use a more accurate method. We base a second off of the radiation cycles of a cesium-133 atom, often called an “atomic clock.”

## How Many Seconds in a Day?

Now that we know what a second really is—**an arbitrary measurement of time used to calculate other, larger units of tim**e—we can start thinking about how many it takes to make up all the other time units.

### How Many Seconds in a Minute

The largest unit after seconds is a minute. **There are 60 seconds in one minute.** Why? Nobody’s really sure, but **it goes all the way back to ancient Babylon.**

### How Many Seconds in an Hour

You may already know that there are 60 minutes in an hour, but how many seconds is that? **To figure it out, we’ll need to multiply.**

60 seconds in one minute and 60 minutes in one hour means that 1hour=60*60. Calculate that out and you’ll find that 1 hour = 3,600 seconds.

### How to Calculate Seconds Back and Forth

**It takes some memorization, but it’s not hard to calculate seconds into minutes, hours, days, or even years**; you can even go in reverse! For example, if you know that something will take 120 seconds but aren’t sure how many minutes that is, you simply divide by 60, the number of seconds in a minute.

Likewise, if you want to know how many seconds are in three days, first you’ll need to calculate how many minutes there are in three days. Three days is 72 hours (24hours*3days), equivalent to 4,320 minutes (72hours*60minutes), or 259,200 seconds (4,320minutes*60seconds).

**You can do this for really big numbers, too.** How many seconds are in a month? Well, the average month is 30.42 days. A day is 24 hours, so the average month is 730.08 hours (30.42days*24hours). 730.08 hours is equal to 43,804.8 minutes (730.08hours*60minutes), or 2,628,288 seconds (43,804.8minutes*60seconds).

## Key Tips for Time Conversions

It’s not a big deal if you can’t memorize this whole table—most people can’t tell you how many seconds are in a decade off the top of their head. **But the calculations are simple math—you just need to know the basics!**

One Minute = 60 Seconds

One Hour = 60 Minutes

One Day = 24 Hours

One Week = 7 Days

One Year = 52 Weeks

One Decade = 10 Years

One Century = 10 Decades

It can be difficult to figure out how many days or weeks are in a month, because months vary in length between 28 and 31 days. **If you find yourself needing to figure things out on a more exact basis, use the number of days in the specific month you’re looking for rather than trying to use an average.**

If a specific month won’t work and you just want an overall sense of the number of days in a month, for example, you know that there are 365 days and 12 months in a year. Divide 365%12

for 30.42, the average number of days in a month. **You don’t have to memorize it—just solve it out!**

**Likewise, you can divide the number of weeks in a year, 52, by the number of months in a year, 12, to get 4.3, the average number of weeks in a month.**