This article shows you how to **convert HH:MM:SS to seconds using Javascript**. You will know the way to use the** split() method and the multiplication and addition operations** to convert it.

**Convert HH:MM:SS to seconds using Javascript.**

**Use the split() method and the multiplication and addition operations**

To convert HH:mm:SS format to seconds, first, we need to split the string into an array with a colon `‘:’`

. We will use the split() method to split it.

Then multiply the hour value in the array by 3600 and the minute value by 60. Finally, we add the value hours and minutes after converting with the original minute value to get seconds.

**Code sample**

```
function convertToSeconds(time){
// Slicing the time string at the colons into an array including hours, minutes and seconds
let timeArr = time.split(':');
// Convert hours and minutes to seconds and add the total number of seconds
let seconds = timeArr[0]*60*60 + timeArr[1]*60 + timeArr[2];
console.log(seconds);
}
convertToSeconds('24:23:24');
convertToSeconds('18:32:05');
```

**Output**

```
8778024
6672005
```

We multiply hours by 3600 and minutes by 60 because 1 hour has 3600 seconds and 1 minute has 60 seconds.

**Use the split() and Math.pow() method**

The Math.pow(x, y) method has the function to calculate the power x to the power y (`x`

). The method will return the result of a mathematical exponent where x is the base and y is the exponent.^{y}

**Syntax**

`Math.pow(x, y)`

**Parameters**:

**x:**the base**y**: the exponent

We also split the string into an array like the first way. Then reverse that array to get the new order of seconds, minutes, and hours.

**Code sample**:

```
let time1 = '15:20:40';
// Slicing time1 at the colons into an array including hours, minutes and seconds
let timeArr = time1.split(':');
// Reverse the timeArr array to seconds, minutes and hours
timeArr.reverse();
let seconds = 0;
// Convert to seconds by multiplying by 60 power i
for(let i = 0; i < timeArr.length; i++){
seconds = seconds + timeArr[i] * Math.pow(60, i);
}
console.log(seconds);
```

Run the for loop on the array after inverting. The first second value corresponds to` i = 0`

, the minute value corresponds to` i = 1`

, and the hour value corresponds to `i = 2`

. We will multiply the values by 60 to the power of` i`

and add up to the seconds.

**Output**

`55240`

**Summary**

Above, I showed you how to **convert HH:MM:SS to seconds using Javascript.** I hope they are helpful to you. To better understand the lesson’s content, practice rewriting today’s examples. And let’s learn more about Javascript in the next lessons here. Have a great day!

**Maybe you are interested**:

- Convert Minutes to Hours and Minutes in JavaScript
- Get the Number of Years between 2 Dates in JavaScript
- Convert a Full Date to a Short Date in JavaScript

Hi, my name is Joni Smith. My job is a programmer. I love learning programming languages, especially C++, C#, php, javascript, html, css. I want to share them with you. I hope my articles will bring a lot of useful knowledge to you.

**Name of the university: **HVNH BA

**Major**: htttql MIS

**Programming Languages**: C++, C#, php, javascript, html, css