How to round up in c#

Question

I want to round up always in c#, so for example, from 6.88 to 7, from 1.02 to 2, etc.

How can I do that?

Solution 1

Use Math.Ceiling()

double result = Math.Ceiling(1.02);

Solution 2

Use Math.Ceiling: Math.Ceiling(value)

Solution 3

If negative values are present, Math.Round has additional options (in .Net Core 3 or later).

I did a benchmark(.Net 5/release) though and Math.Ceiling() is faster and more efficient.

Math.Round( 6.88, MidpointRounding.ToPositiveInfinity) ==> 7   (~23 clock cycles)
Math.Round(-6.88, MidpointRounding.ToPositiveInfinity) ==> -6  (~23 clock cycles)

Math.Round( 6.88, MidpointRounding.AwayFromZero)       ==> 7   (~23 clock cycles)
Math.Round(-6.88, MidpointRounding.AwayFromZero)       ==> -7  (~23 clock cycles)

Math.Ceiling( 6.88)                                    ==> 7   (~1 clock cycles)
Math.Ceiling(-6.88)                                    ==> -6  (~1 clock cycles)

Comments

[Talljoe]

possible duplicate of how to always round up to the next integer

[Felice Pollano]

Try to write Math. and look with enough attention to all the function you see

[Henk Holterman]

Incomplete specs. What should -1.02 become?

[Bek Raupov]

simple googling would have helped :)

[Todd Painton]

yep, I googled, first on the list was this post... Thanks for asking.

[Scott]

First one I saw. This is more clear than using awayfromzero. Thanks!

[cHao]

Clearer, and correct. :) AwayFromZero is used for something else, and would break for you in this case.

[Kyle Delaney]

Is there an option that returns an int or long instead?

[henry.dv]

@KyleDelaney no, but you can easily cast it via (int) Math.Ceiling(someDouble);.

[Kyle Delaney]

@henry.dv - I wonder why a rounding function would return a double to begin with

[RedGreenCode]

@KyleDelaney stackoverflow.com/questions/5693468/…

[eKKiM]

Math.Round has the advantage that it has the possibility to round to a given amount of decimals. While this is not possible with Math.Ceiling!