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var number = 0.08;
var newNumber = Math.round(number * 4) / 4 //round to nearest .25

With the code above i can round to nearest .25. However i only want it to round up. Whereby:

0.08 = 0.25
0.22 = 0.25
0.25 = 0.25
0.28 = 0.5

How will that be possible?

var number = 0.08;
var newNumber = Math.round(number * 4) / 4 //round to nearest .25

With the code above i can round to nearest .25. However i only want it to round up. Whereby:

0.08 = 0.25
0.22 = 0.25
0.25 = 0.25
0.28 = 0.5

How will that be possible?

• javascript
• rounding

Share Improve this question Follow edited Aug 2, 2017 at 7:52 CloudSeph asked Aug 2, 2017 at 6:42 CloudSephCloudSeph 88344 gold badges1616 silver badges3939 bronze badges 1

• Will you only be dealing with numbers up to 2DP? – toastrackengima Commented Aug 2, 2017 at 6:44

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5 Answers 5

Sorted by: Reset to default 9

What you effectively want to do is to take the ceiling of the input, but instead of operating on whole numbers, you want it to operate on quarters. One trick we can use here is to multiply the input by 4 to bring it to a whole number, then subject it to JavaScript's Math.ceil() function. Finally, divide that result by 4 to bring it back to its logically original start.

Use this formula:

Math.ceil(4 * num) / 4

function getCeiling(input) {
    return Math.ceil(4 * input) / 4;
}

console.log("input: 0.08, output: " + getCeiling(0.08));
console.log("input: 0.22, output: " + getCeiling(0.22));
console.log("input: 0.25, output: " + getCeiling(0.25));
console.log("input: 0.28, output: " + getCeiling(0.28));

Your may want to us Math.ceil():

ceil() round a number upward to its nearest integer.

console.log(Math.ceil(0.08 * 4) / 4);    // 0.25
console.log(Math.ceil(0.22 * 4) / 4);    // 0.25
console.log(Math.ceil(0.25 * 4) / 4);    // 0.25
console.log(Math.ceil(0.28 * 4) / 4);    // 0.5

Tim Biegeleisen has definitely the best answer, but if you want a more 'simple' approach you can basically just write your own function, something like:

var round = (num) => {
  if (num <= 0.25) {
      return 0.25;
  } else if (num > 0.25 && num <= 0.5) {
      return 0.5;
  } else if (num > 0.5 && num <= 0.75) {
      return 0.75;
  } else if (num > 0.75 && num <= 1.0) {
      return 1.0;
  } else {
      return null;
  }
};

When called it will reproduce the results you want:

round(0.08); // 0.25
round(0.22); // 0.25
round(0.25); // 0.25
round(0.28); // 0.5

User Math.ceil() function to round up a number.

Math.floor() - to round down.

var number = 0.08;
var newNumber = Math.ceil($scope.newAmt * 4) / 4 //round to nearest .25

The big issue is you using

Math.round($scope.newAmt * 4) / 4

This will always round based on the standard way of rounding as we know it. You could use

Math.ceil($scope.newAmt * 4) / 4

as this will always round up. It's down-rounding brother is

Math.floor()

by the way.

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