Keyword density measures how frequently your target keyword shows up on a page relative to total words. Calculate it by dividing keyword mentions by total word count, then multiply by 100. A 500-word article with your keyword appearing 10 times has a 2% density. Google stopped caring about precise density percentages over a decade ago. Early SEO obsessed over hitting 3–5% because ranking algorithms were simpler—more mentions often meant higher rankings. That created spammy content stuffed with repetitive phrases. Modern algorithms prioritize semantic understanding, so they recognize synonyms, related terms, and topic clusters instead of counting exact matches. In practice, keyword density still matters as a sanity check, not a target. If your keyword appears 0.5% of the time in a 1,200-word article, you probably under-optimized and need clearer focus. If it hits 8%, readers will notice the repetition and bounce, which tanks your rankings anyway. The sweet spot usually lands between 1–3% when you write naturally for humans. What actually moves the needle: using your primary keyword in the title tag, H1, first 100 words, and a few subheadings, then sprinkling variations and related terms throughout. Ottawa SEO runs content briefs that map primary keywords, secondary phrases, and LSI terms so writers cover the topic thoroughly without gaming a percentage. We see far better results optimizing for search intent and comprehensive coverage than chasing density metrics. Watch out for over-optimization penalties if you force keywords into awkward spots or repeat the exact phrase robotically. Google's spam algorithms flag unnatural patterns. Also remember density ignores placement—ten mentions buried in footer text matter less than three mentions in strategic header and intro positions. Bottom line: treat keyword density as a diagnostic, not a goal. Write for clarity and completeness first, then audit whether your target terms appear often enough to signal relevance without sounding repetitive. That balance wins rankings and keeps readers engaged.