Counting rows w/o counter

I am working on a project, and my not-so-stellar method of marking rows on a piece of paper was interrupted by a phone call, but i kept knitting. I am doing just plain garter stitch, how do i count the rows exactly? Thank you in advance :smiley:

Garter stitch looks like

bumps
groove
bumps
groove
bumps
groove

Each line of bumps is a row. Each groove is another row.

You can also count the ridges and multiply by 2 for garter st.

I am so glad you asked this question. Now I understand too!