Content SEO Optimization Score
Score your content's on-page SEO quality based on word count, keyword density, heading structure, and internal linking. Use it when writing or auditing articles to identify specific gaps before publishing.
About this calculator
On-page SEO optimization balances multiple factors: content depth (word count), keyword usage (density), structural clarity (heading tags), and site architecture signals (internal links). The formula is: Score = min(100, ((log₁₀(wordCount) × 25) + (max(0, 5 − |keywordDensity − 1.5|) × 8) + (min(headingTags, 10) × 3) + (min(internalLinks, 15) × 2)) × contentTypeMultiplier). Word count uses a logarithmic scale to reward depth without infinitely rewarding padding. Keyword density is scored on a penalty curve centered at 1.5%: values too far above or below that optimum lose points, discouraging both keyword stuffing and under-optimization. Heading tags are capped at 10 to reward structure without rewarding excessive fragmentation. Internal links are capped at 15, reflecting best-practice guidance. Guide-format content earns a 10% bonus (multiplier 1.1) for its typically greater depth and topical comprehensiveness.
How to use
Score a blog post with 1,500 words, 1.8% keyword density, 7 heading tags, and 8 internal links (content type = blog, multiplier = 1.0). 1. Word count term: log₁₀(1500) × 25 ≈ 3.176 × 25 = 79.4 2. Density term: max(0, 5 − |1.8 − 1.5|) × 8 = (5 − 0.3) × 8 = 4.7 × 8 = 37.6 3. Headings term: min(7, 10) × 3 = 7 × 3 = 21 4. Internal links term: min(8, 15) × 2 = 8 × 2 = 16 5. Sum: 79.4 + 37.6 + 21 + 16 = 154 6. Apply multiplier & cap: min(100, 154 × 1.0) = 100 Score = 100/100. This 1,500-word, well-structured post already hits the ceiling — a good sign before publishing.
Frequently asked questions
What is the ideal keyword density for on-page SEO content optimization?
Most SEO practitioners and the formula used here center optimal keyword density around 1.5%, meaning your primary keyword appears roughly 1–2 times per 100 words. Densities significantly below 1% may signal to search engines that the content isn't strongly focused on the target topic. Conversely, densities above 3% risk triggering keyword-stuffing filters, which can actively suppress rankings. The penalty curve in this calculator scores density symmetrically around 1.5%, so both under-use and overuse reduce your score equally. Natural writing that addresses the topic comprehensively typically lands in the 1–2% range without deliberate counting.
How many internal links should I include in a blog post for best SEO results?
Internal linking helps search engines crawl your site, distributes page authority, and signals topical relationships between your content. Most SEO guidance recommends 3–10 contextual internal links for a standard blog post, rising to 10–15 for long-form guides. This calculator caps the internal link score at 15 links, reflecting the point of diminishing returns — beyond that, links may appear spammy or distract users. Quality matters as much as quantity: each internal link should lead to a genuinely relevant page and use descriptive anchor text that helps both users and crawlers understand the destination.
Why does content word count use a logarithmic scale in the SEO optimization score?
A logarithmic scale means each additional 1,000 words contributes progressively less to the score, which accurately reflects SEO reality. Going from 300 to 1,000 words is a dramatic improvement in content depth and likely to impact rankings significantly. Going from 5,000 to 6,000 words, on the other hand, makes little practical difference to how well a page covers a topic. A linear scale would wrongly suggest that a 10,000-word page is 10× better than a 1,000-word page. The log₁₀ function rewards meaningful depth while preventing the score from being gamed simply by inflating word count with low-quality filler content.