# Using JavaScript Math.ceil() method

Posted on December 29, 2020

The JavaScript `Math.ceil()` method is a method from Math object that’s used to round a decimal number up to the closest round number. For example, a number variable of `7.2` will be rounded up to `8` when you pass it into the method.

The syntax for this method looks as follows:

``````Math.ceil(7.2); // returns 8
``````

You can pass the initial number as a variable:

``````let score = 7.2;

Math.ceil(score); // returns 8
``````

The returned number can also be stored in a variable like this:

``````let score = 7.2;

let roundedScoreUp = Math.ceil(score);

console.log(roundedScoreUp); // 8
``````

The method accepts only one parameter of `number` value. If you pass a `string`, an `object`, or an `array` to the method, it will return `NaN` which stands for `Not a Number`:

``````Math.ceil("Hello there!");
Math.ceil([1, 2, 3]);
Math.ceil({ name: "Andy" });

// returns NaN
``````

When you pass a `boolean` value of `true` or `false` it will return `1` for `true` and `0` for `false`:

``````Math.ceil(true);
// returns 1

Math.ceil(false);
// returns 0
``````

When you pass more than one parameter, JavaScript will simply ignore the next parameters and operate on the first one:

``````Math.ceil(5.5, 2, 80);

// returns 6
``````

## Using Math.ceil() on negative numbers

The method will also round a negative number up. Negative numbers get smaller the farther they are from zero, so the number value of `-55.7` will be rounded to `-55` and not `-56`:

``````Math.ceil(-55.7);

// returns -55
``````

## Other Math rounding method

If you want to round the number up when its decimal value is `.5` or higher and round the number down when its decimal value is lower than `.5` then you need to use `Math.round()` method.

When you want to round the number down instead of up (from `7.8` to `7`) then you need to use the `Math.floor()` method.

More on JavaScript:

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