Calculate z-scores from GWAS summary stats

Hello,

I need to calculate the z-scores from meta-GWAS summary stats. The association file has the following header

rs_id   Allele1 Allele2 Freq1   Effect  StdErr  P.value

The ‘effect’ is the Beta coefficent. My understanding is

z-score=Effect/StdErr

Is that correct ? Also, are there any R packages that can do this ?

Many thanks