Powershell Round Up Function

Question

I would like to round up to two decimal places in Powershell.

I start with the double "178.532033". If I use the Excel ROUNDUP function to two decimal places I get "178.54".

=ROUNDUP(A1,2)

However, if I use the Round function contained within the Math class in Powershell I get the result "178.53" (because I am rounding as opposed to rounding up):

$value = 178.532033

Write-Output = ([Math]::Round($value, 2))

Is there a way to round up to two decimal places in Powershell?

Are you looking for [this](https://stackoverflow.com/questions/48864295/powershell-int-variable-with-decimal-number)? See [the detailed explanation](https://stackoverflow.com/questions/48864295/powershell-int-variable-with-decimal-number/48893799#48893799) by [mklement0](https://stackoverflow.com/users/45375/mklement0). — Vivek Kumar Singh, Sep 03 '18 at 11:07
@KirillPashkov The division returns a double value. [See here](https://stackoverflow.com/questions/588004/is-floating-point-math-broken) for why rounding that result is not optional. — Ansgar Wiechers, Sep 03 '18 at 13:53
A rational round up function would give 178.53 if I understand it correctly. You'd get 178.54 if the thousandths value was 5-9. — duffymo, Sep 04 '18 at 15:00
@duffymo That would be normal rounding behavior. The OP wants to replicate the behavior of the Excel [`ROUNDUP()`](https://support.office.com/en-us/article/ROUNDUP-function-F8BC9B23-E795-47DB-8703-DB171D0C42A7) function, which always rounds UP (hence the name). — Ansgar Wiechers, Sep 15 '18 at 23:26

Graham · Answer 1 · 2021-02-27T17:09:31.917

This is handled easily by the ceiling and floor methods of the math class.

Script:

$a = 657
$b = 234

$a/$b
[math]::floor($a/$b)
[math]::ceiling($a/$b)

Output:

2.80769230769231
2
3

If you want to round to two decimal places, multiply by 100 before using floor/ceiling then divide the result by 100.

I find that you are rarely going to be the last person to edit a PowerShell script, and keeping them simple is key to not getting an e-mail a year later wondering what you were doing with a complex transformation in a script that no longer works.

score 6 · Answer 2 · answered Feb 21 '20 at 03:55

6

Just add 0.005 before rounding:

$value = 178.532033
Write-Output = ([Math]::Round($value + 0.005, 2))

This takes the interval [1.000, 1.010) to [1.005, 1.015). All the values in the first interval ROUNDUP(2) to 1.01, and all the values in the second interval ROUND(2) to 1.01.

In general, if rounding to k places after the decimal, add 0.5/10^k to round up, or subtract that to round down, by rounding the result normally.

answered Feb 21 '20 at 03:55

Patrick87

27,682
3
38
73

Simple, effective, beautiful. Great answer. – Arbiter Mar 02 '21 at 20:58
Goes the wrong way for negative values – Walter A Mar 20 '23 at 14:27

score 1 · Answer 3 · edited Feb 21 '20 at 05:57

1

Rounddown:

$a = 9;
$b = 5;
[math]::truncate($a/$b)

Roundup:

$a = 9;
$b = 5;
if ( ($a % $b) -eq 0 )
{
  $a/$b
}
else 
{
  [math]::truncate($a/$b)+1
}

edited Feb 21 '20 at 05:57

Florian Castellane

1,197
2
14
38

answered Feb 21 '20 at 02:56

lijun1234

21
2

score 0 · Answer 4 · answered Sep 07 '22 at 10:38

0

I want the returned value padded with zeros.

Given the value 10.99822

[Math]::Ceiling(10.99822 * 100)/100

Returns: 11

To add zero padding:

"{0:n2}" -f ([Math]::Ceiling(10.99822 * 100)/100)

Returns: 11.00

answered Sep 07 '22 at 10:38

woter324

2,608
5
27
47

Powershell Round Up Function

4 Answers4