How to round a decimal up?

Question

Given a decimal '96.154', how can I ensure that it is always rounded up to 96.16 (as opposed to normal rounding to 2 decimals which would give 96.15).

How does 96.154 round up to 96.16 and not round down to 96.15? It would be good to detail the specification for how rounding should work — Russ Cam, Aug 03 '12 at 11:14
Check out this link http://stackoverflow.com/questions/11740989/rounding-decimal-value/11741129#11741129 — sabz23, Aug 03 '12 at 11:15
Do you care about negative number? Should they be rounded up (toward zero) as well? — Michael Graczyk, Aug 03 '12 at 11:18

score 19 · Accepted Answer · edited Aug 03 '12 at 11:18

19

Kind of hacky but a very intuitive way to do so:

var val = 96.154M;

var result = Math.Ceiling(val * 100) / 100.0M;

edited Aug 03 '12 at 11:18

Oded

477,625
97
867
998

answered Aug 03 '12 at 11:16

Yuck

47,217
13
101
134

Not the most ideal as you say but looks like the best solution – Adam Goss Aug 03 '12 at 11:50

score 7 · Answer 2 · answered Aug 03 '12 at 11:18

7

You can add 0.005 to the value and then round the result.

answered Aug 03 '12 at 11:18

Bruno Ferreira

932
9
22

1

genius but, depends if you always want to round away from zero, what about negatives? – Jodrell Aug 03 '12 at 11:26
@Jodrell The title of the question says it all "always up". By the way, I upvoted the comment about negative numbers. – Bruno Ferreira Aug 03 '12 at 11:27
4

This will not work when the value is `96.150`, since that would round it to `96.16`, which is incorrect, since that it should stat `96.15`. – Steven Aug 03 '12 at 11:45

Ben Ripley · Answer 3 · 2016-09-09T12:57:18.210

6

I think your looking for the Math.Ceiling method.

You could combine this with a multiplier to specify how many decimal places to round. Like this,

public float roundUp(float number, int numDecimalPlaces)
{
    double multiplier = Math.Pow(10, numDecimalPlaces))

    return Math.ceiling(number*multiplier) / multiplier;
}

edited Sep 09 '16 at 12:57

answered Aug 03 '12 at 11:16

Ben Ripley

2,025
21
30

score 0 · Answer 4 · answered Jul 09 '16 at 15:02

Here is the code of a roundUp method for a value and base fraction. The base fraction you should use for your question is 0.05M. However the method can be used for other common scenario which is base fraction 0.5M; And you can apply it in interesting ways like for example using a base fraction of 0.3M. Well I hope it should answer your questions, have fun :

static decimal roundUp(decimal aValue, decimal aBaseFraction)
{
   decimal quotient = aValue / aBaseFraction;
   decimal roundedQuotient = Math.Round(quotient, 0);
   decimal roundAdjust = 0.0M;
   if (quotient > roundedQuotient)
   {
      roundAdjust = aBaseFraction;
   }
   return roundAdjust + roundedQuotient * aBaseFraction;
}

score 0 · Answer 5 · answered Nov 04 '17 at 16:33

Here is my version of a RoundUp method, In this can specific decimal

void Main()
{
    Console.WriteLine(RoundUp(2.8448M, 2));
    //RoundUp(2.8448M, 2).Dump();
}

public static decimal RoundUp(decimal numero, int numDecimales)
{
    decimal valorbase = Convert.ToDecimal(Math.Pow(10, numDecimales));
    decimal resultado = Decimal.Round(numero * 1.00000000M, numDecimales + 1, MidpointRounding.AwayFromZero) * valorbase;
    decimal valorResiduo = 10M * (resultado - Decimal.Truncate(resultado));

    if (valorResiduo < 5)
    {
        return Decimal.Round(numero * 1.00M, numDecimales, MidpointRounding.AwayFromZero);
    }
    else
    {
        var ajuste = Convert.ToDecimal(Math.Pow(10, -(numDecimales + 1)));
        numero += ajuste;
        return Decimal.Round(numero * 1.00000000M, numDecimales, MidpointRounding.AwayFromZero);
    }
}

How to round a decimal up?

5 Answers5

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