I need to replicate a form where a user inputs values and the form sends the user values as well as a summed total of those values. Each field will have a value attached to it and this value is multiplied by the user's input.

For example:

Item1 = 1
Item2 = 0.25
Item3 = 0.95

So if the user enters

Item1 = 3
Item2 = 1
Item3 = 2

Then the form will calculate the total as

Item1 : 1 x 3 = 3
Item2 : 0.25 x 1 = 0.25
Item3 : 0.95 x 2 = 1.9
TOTAL = 5.15

So the form would send the user input as normal AND the total.

Any suggestions on whether the default form can do this? Maybe hidden fields?
Or whether I need to custom code one and if so then pointers in the right direction would be appreciated.

Dex