# Rounddown Calculation issue or confusion?

#### blewispunk

##### New Member
Hello,

I'm trying to use the rounddown function and getting some odd results that seem like a bug but maybe I'm confused by the function.

I have
A1 = 0.110
A2 = 0.101

My function is =ROUNDDOWN(A1-A2,3)

I keep getting a result of 0.008 even though simple math should result in 0.009. I would think this would be due to extra digits being in cell A1 or A2 but the values entered are exactly as shown here. If I try different values it seems to be working correctly with other combinations I've tried but this one is goofy. When I change the calculation to =ROUNDDOWN(A1-A2,4) I get a result of 0.0089, so it is doing some incorrect math.

Any thoughts on this? I'm using Excel 2007.

### Excel Facts

Which Excel functions can ignore hidden rows?
The SUBTOTAL and AGGREGATE functions ignore hidden rows. AGGREGATE can also exclude error cells and more.

#### zzjasonzz

##### Well-known Member
its rounding it down? what result would you expect?

0.0089 rounded down to 3 s.f. is 0.008

#### barry houdini

##### MrExcel MVP
Due to the way Excel calculates you sometimes get "rounding errors" so in this case instead of 0.009 the result of A1-A2 is actually 0.00899999999999999 [according to Excel] hence the result of 0.008 when rounded down. You can get round that by rounding within the rounddown, i.e.

=ROUNDDOWN(ROUND(A1-A2,5),3)

See here for more details

Replies
3
Views
142
Replies
4
Views
176
Replies
1
Views
159
Replies
6
Views
203
Replies
3
Views
303

1,130,307
Messages
5,641,440
Members
417,209
Latest member
Agbarker

### We've detected that you are using an adblocker.

We have a great community of people providing Excel help here, but the hosting costs are enormous. You can help keep this site running by allowing ads on MrExcel.com.

### Which adblocker are you using?

1)Click on the icon in the browser’s toolbar.
2)Click on the icon in the browser’s toolbar.
2)Click on the "Pause on this site" option.
Go back

1)Click on the icon in the browser’s toolbar.
2)Click on the toggle to disable it for "mrexcel.com".
Go back

### Disable uBlock Origin

Follow these easy steps to disable uBlock Origin

1)Click on the icon in the browser’s toolbar.
2)Click on the "Power" button.
3)Click on the "Refresh" button.
Go back

### Disable uBlock

Follow these easy steps to disable uBlock

1)Click on the icon in the browser’s toolbar.
2)Click on the "Power" button.
3)Click on the "Refresh" button.
Go back