Excel formula help

[Cold Fusion]

I am trying to automate a volume calculation in a spreadsheet and am struggling to spot the error in my equation.

The equation has two sets of inputs depending on whether it is a rectangle or a polygon but some inputs are shared. Below is an example of a 5x5x1 volume with a working space allowance around the perimeter and them the excavation depth

Rectangle Calc:
=((5+((500/1000)*2))*(5+((500/1000)*2)))*((1+(25.61-24.81))+100/1000)

= 68.40m3

Polygon Calc:
=(25+((20*1*(500/1000)))+(4*(500/1000)*500/1000))*((1+(25.61-24.81))+100/1000)

=68.40m3

But when combined it throws out a slightly different answer:

=(((5+((500/1000)*2))*(5+((500/1000)*2)))+(25+((20*(500/1000)))+(4*(500/1000)*500/1000)))*((1+(25.61-24.81))+100/1000)

=70.30m3

This 1.90m3 difference appears to be related to the depth calculation but I cant understand why it adding this to the total.

 

[Diddums x]

 

[Pho]

Your third formula gives me 136.8 in Excel 2016?

edit: as does Google calculator

 

[RoyMi6]

If I put those calculations into excel I get:
68.4
68.4
136.8

Apart from the fact you appear to be missing a "1*" in the second part of your combined question "(25+((20*1*(500/1000)))+(4*(500/1000)*500/1000)))" (which is obviously academic given it doesn't change the result in this instance, but might play into your problems if that 1 relates to the depth of the volume calculation) it appears to work as expected no?

 

[Gixer]

I get the same results as Roy in Excel with those formula so looks as though it works as you intend it to.

 

[MrRockliffe]

Remember that excel uses radians automatically

Just noticed no circle equation - will take a look and see what’s going on

Edit: getting the same as others

 

[doogs]

In Excel 2013 I get 68.4, 68.4, and 136.8 so, seems to be working as intended.

 

[Tomsk]

I am trying to automate a volume calculation in a spreadsheet and am struggling to spot the error in my equation.

The equation has two sets of inputs depending on whether it is a rectangle or a polygon but some inputs are shared. Below is an example of a 5x5x1 volume with a working space allowance around the perimeter and them the excavation depth

Rectangle Calc:
=((5+((500/1000)*2))*(5+((500/1000)*2)))*((1+(25.61-24.81))+100/1000)

= 68.40m3

Polygon Calc:
=(25+((20*1*(500/1000)))+(4*(500/1000)*500/1000))*((1+(25.61-24.81))+100/1000)

=68.40m3

But when combined it throws out a slightly different answer:

=(((5+((500/1000)*2))*(5+((500/1000)*2)))+(25+((20*(500/1000)))+(4*(500/1000)*500/1000)))*((1+(25.61-24.81))+100/1000)

=70.30m3

This 1.90m3 difference appears to be related to the depth calculation but I cant understand why it adding this to the total.

EDIT : My mistake. No extra bracket.

 

[NoobCannon]

Classic