Rounding Significant Figures in Excel

Use the following formula to round a value to a certain number of sigfigs:

=ROUND(value,sigfigs-(1+INT(LOG10(ABS(value)))))

2 comments:

Vishal said...

How is this different from
=ROUND(value,sigfigs-1)
I am trying to understand the need for using log and such, because I tried this for negative values and negative sigfigs.

The Chairman said...

Not sure if I can answer your question, but I would like to submit an alternative that I like to use.

I often use excel to generate values for my games, and I often want to round my cost formulas to only the first 2 sigfigs. (35,124,124 = 35,000,000 etc...)

so I use
=ROUND(value,LEN(INT(value))*-1+2)

the INT function only does anything if you have decimals which you don't want the LEN to read

the last +2 can be changed to round to a different number of first sig figs.