Tracy,

Daddy doesn't seem to be around a the moment. I would suggest making the
meter reading entries text by formatting the cells as text *before* entering
the reading or preceding them with an apostrophe if they are already
entered, (so that the leading zeros will be counted as characters), then
using Daddy's excellent formula, modify it to:

=MOD(D2-C2,10^LEN(D2))


--
HTH

Sandy
In Perth, the ancient capital of Scotland


with @tiscali.co.uk


"Maria Tracey" wrote in message
...
"daddylonglegs"
wrote in
message news:daddylonglegs.2691am_1145009404.7613@excelfor um-nospam.com...

If you have this months meter reading in D2 and last months in C2 then
this formula will give the units used

=MOD(D2-C2,100000)

If you set up your spreadsheet with each meter on a separate row,then
you can have a meter identifier in column A and first date's readings
in column C, second date in D etc. (row 1 contains meter reading date).
In B2 copied down you could use this formula

=MOD(LOOKUP(100000,C2:IV2)-LOOKUP(100000,C2:IV2,B2:IU2),100000)

which will automatically give you the units used for the last month


--
daddylonglegs
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Hi Daddy,

I've set the sheet up as you suggested and it works like a dream (I think
!)

I've discovered though a few little quirks from the meter readings .......

Some of the meters have 5 dials hence 5 digits and some have 6 therefore 6
digits and there is also one with 7 digits.

How do I modify the formula to take into account those ?

Also, and this is a tricky one for me......

Some of the readings from the meters have a multiplier like times 100 or
times 1000 and another which is divide by 1000

So is it possible to enter the reading in its native format and have Excel
apply the correct times or divide for each one ?

Thanks for your help

Maria