Crochet has an advantage over knitting when it comes to counting: because each stitch is built and finished individually rather than held live on a needle, the rows tend to be more visually distinct. You can usually see clear horizontal lines where one row ends and the next begins, especially in taller stitches like double or treble crochet, where the row height itself makes the boundary obvious.
That said, crochet has its own set of counting mistakes that are common enough to be worth addressing directly, and almost every crocheter runs into at least one of them at some point, usually early on and usually on a project where getting it right actually mattered.
The foundation chain is not row one
This is the single most common counting error in crochet, and it happens to beginners and experienced crocheters alike when they're tired or distracted. The foundation chain — the initial row of chain stitches you make before your first real row of stitches — is not counted as a row. It's the base the first row is worked into, similar to how a cast-on edge isn't counted as a knit row.
Your actual row one is the first row of stitches worked into that chain, whether that's single crochet, double crochet, or anything else. If you count the chain as row one, every subsequent row count will be off by exactly one for the rest of the project, which can be a real problem in patterns with row-specific shaping instructions or a stitch pattern that repeats over an odd number of rows.
Reading rows once they're built
Turn your work so you're looking at the side of the fabric, not the front. You'll see a stacked series of horizontal lines, each representing a completed row. Count from the foundation chain up to your hook. For most standard stitches this is fairly unambiguous once you know what you're looking at, though taller stitches like trebles can sometimes make individual rows look thicker or bulkier, which occasionally causes people to second-guess whether they're seeing one row or two — they are seeing one, it's just a physically taller stitch.
Some crocheters count the bumps or ridges on the back of the work instead of the front, and either method is fine as long as you're consistent about which one you use for a given project. Switching between counting methods partway through a single piece is a good way to introduce an off-by-one error without realizing it.
The other common mistakes
Missed edge stitches are the second most frequent issue. It's easy to skip the first or last stitch of a row, especially the turning chain, which sometimes counts as a stitch and sometimes doesn't depending on the pattern and stitch height — always check what the specific pattern says about this, since conventions differ between designers. A missed edge stitch doesn't always throw off your row count directly, but it does distort the shape of the piece, which then makes visual row-counting harder on every subsequent row because the edges no longer line up cleanly.
The other issue is specific to granny squares, motifs, and anything worked in joined rounds rather than straight rows — the counting logic there is different enough that it deserves its own explanation, and it's covered in the granny square guide linked below if that's the kind of project you're working on.
For a straightforward flat piece — a scarf, a dishcloth, a simple garment panel — a digital counter removes the foundation-chain ambiguity entirely, because you decide when row one starts by tapping the counter, and from that point on the number on screen is simply correct regardless of how the stitches look or how tired you are when you sit back down to the project.