How do you round a number to two decimal places in C#?

Question

Here's some examples:

decimal a = 1.994444M;

Math.Round(a, 2); //returns 1.99

decimal b = 1.995555M;

Math.Round(b, 2); //returns 2.00

You might also want to look at bankers rounding / round-to-even with the following overload:

Math.Round(a, 2, MidpointRounding.ToEven);

There's more information on it here.

Try this:

twoDec = Math.Round(val, 2)

If you'd like a string

> (1.7289).ToString("#.##")
"1.73"

Or a decimal

> Math.Round((Decimal)x, 2)
1.73m

---

But remember! Rounding is not distributive, ie. round(x*y) != round(x) * round(y). So don't do any rounding until the very end of a calculation, else you'll lose accuracy.

Personally I never round anything. Keep it as resolute as possible, since rounding is a bit of a red herring in CS anyway. But you do want to format data for your users, and to that end, I find that string.Format("{0:0.00}", number) is a good approach.