Convert Seconds to Minutes and Seconds in JavaScript

Convert Seconds to Minutes and Seconds in JavaScript #

To convert seconds to minutes and seconds:

1. Get the number of full minutes by dividing the seconds by 60.
2. Get the remainder of the seconds.
3. Optionally, format the minutes as seconds as mm:ss.

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const totalSeconds = 565;

// 👇️ get number of full minutes
const minutes = Math.floor(totalSeconds / 60);

// 👇️ get remainder of seconds
const seconds = totalSeconds % 60;

function padTo2Digits(num) {
  return num.toString().padStart(2, '0');
}

// ✅ format as MM:SS
const result = `${padTo2Digits(minutes)}:${padTo2Digits(seconds)}`;
console.log(result); // 👉️ "09:25"

The first step is to get the number of full minutes, by dividing the seconds by 60 and rounding the result down.

The Math.floor function, rounds a number down if the number has a decimal, otherwise it returns the number as is.

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console.log(Math.floor(9.99)); // 👉️ 9
console.log(Math.floor(9.01)); // 👉️ 9
console.log(Math.floor(9)); // 👉️ 9

We used the modulo (%) operator to get the remainder of seconds.

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const totalSeconds = 565;

// 👇️ get remainder of seconds
const seconds = totalSeconds % 60;
console.log(seconds); // 👉️ 25

This means that when we divide totalSeconds by 60, we get a remainder of 25 seconds.

In other words, once we subtract all the full minutes from totalSeconds, we have 25 seconds left.

The next step is to format the minutes as seconds as mm:ss, e.g. 05:45.

Our padTo2Digits function, takes care of adding a leading zero if the minutes or seconds only contain a single digit (are less than 10).

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function padTo2Digits(num) {
  return num.toString().padStart(2, '0');
}

console.log(padTo2Digits(1)); // 👉️ '01'
console.log(padTo2Digits(5)); // 👉️ '05'
console.log(padTo2Digits(10)); // 👉️ '10'

We want to make sure the result does not alternate between single and double digit values depending on the minutes and seconds.