Rounding to 4 Decimal Places in C#

Question

I have the value

8443.64625

and want to round it to 4 decimal places. When I use decimal.Round(8443.64625, 4, MidpointRounding.AwayFromZero)it gives the value

8443.6463

. So it seems to be round up because of the 5. What can I do to make it return the value

8443.6462

. I could convert it to string and then truncate after 4dp but I feel there has to be a more efficient way?

Maybe https://stackoverflow.com/questions/12680121/c-sharp-midpointrounding-down-to-zero — Matthew Watson, Mar 02 '20 at 13:47

score 0 · Answer 1 · answered Mar 02 '20 at 13:48

0

You Can Use this it will work fine Just Try it once. It will give You the result that you want. that is 8443.6462.

    Math.Round(8443.64625, 4)

answered Mar 02 '20 at 13:48

ROHAN TONGLE

77
6

2

That actually rounds to the nearest EVEN number - try `Math.Round(8445.64635, 4)` - it will return `8445.6464` (which isn't what the OP wants, they want that to return `8445.6463`). – Matthew Watson Mar 02 '20 at 13:52
@MatthewWatson I want to return 8443.6462 which this seems to do – Bad Dub Mar 02 '20 at 13:59
@BadDub But what do you want `8445.64635` to return? (This is not the same number as `8445.64625` - look at it carefully! One ends with `35` and the other with `25`.) – Matthew Watson Mar 02 '20 at 14:05

Bad Dub · Accepted Answer · 2020-03-02T14:16:23.350

It was suggested to use decimal.Round(8443.64625, 4, MidpointRounding.ToEven) by someone but that comment seems to have been removed.

MidpointRounding.ToEven works for the scenario I posted yes, but if the value was 8443.64629 it would produce 8443.6463. I need it to truncate without rounding.

I came across this answer which seems to truncate after 4dp with no rounding.

public static decimal TruncateValue(this decimal num, int significantDigits)
{
    decimal y = (decimal)Math.Pow(10, significantDigits);
    return Math.Truncate(num * y) / y;
}

score 0 · Answer 3 · edited Mar 02 '20 at 14:50

0

This works

var num = 8443.64625;

var roundedNum = Math.Round(num, 4, MidpointRounding.ToEven);

edited Mar 02 '20 at 14:50

ChrisF

134,786
31
255
325

answered Mar 02 '20 at 14:10

Edivan Jr.

1

It works for the scenario I posted yes, but if the value was 8443.64629 it would produce 8443.6463. I need it to truncate without rounding. – Bad Dub Mar 02 '20 at 14:14

score 0 · Answer 4 · answered Mar 02 '20 at 14:26

0

I don't know if this has been answered yet but, you could use Truncate.

It's not 'rounding' per se but you would get the result I believe you want.

ie:

double num = 8443.64625;
Math.Truncate(10000 * num) / 10000

returns

8443.6462

answered Mar 02 '20 at 14:26

JamesS

2,167
1
11
29

Rounding to 4 Decimal Places in C#

4 Answers4