Maintenance cost depends on six things most calculators ignore: your platform (WordPress vs custom React differ 3-4× in monthly cost), your site size, your service tier (DIY through full-service), the hidden costs (premium plugins, SEO tools, CDN, paid SSL), and the opportunity cost of doing it yourself. This calculator models all of them across 6 platforms × 4 sizes × 5 service tiers, with pricing benchmarks from WPBuffs, Maintainn, SiteCare, GoDaddy Pro, WP Engine, Kinsta, Shopify Partners, Webflow, Vercel, Cloudflare, Clutch 2024, and GoodFirms 2024.
Math: if your billable rate is $75/hr and a Basic agency tier costs $100/mo, the agency pays back when DIY would take you more than ~1.3 hr/mo. For a typical small WordPress site, that's almost always — security patches alone run 2-3 hr/mo when something breaks. DIY is rational only for static sites (Hugo, Astro, Eleventy) on free-tier hosting (Cloudflare Pages, GitHub Pages), or when your time is genuinely worth less than $30-50/hr. The calculator surfaces both your DIY opportunity cost and the agency comparison side-by-side.
Premium plugins/themes: $300-1,000/yr for serious WordPress sites (Yoast Premium, Wordfence, page builder licenses, Klaviyo). SEO monitoring: Ahrefs/SEMrush start at $99-199/mo for serious work. CDN: Cloudflare Pro $20/mo, Fastly higher. Paid SSL: usually $0 with Let's Encrypt, but EV/wildcard certs run $50-300/yr. These add $1,500-5,000/yr on top of base hosting + maintenance — and most agency proposals don't mention them upfront. The calculator lets you toggle each to see real total cost of ownership.
Math: if your billable rate is $75/hr and a Basic agency tier costs $100/mo, the agency pays back when DIY takes you more than ~1.3 hr/mo. For a typical small WordPress site, that's almost always — security patches alone run 2-3 hr/mo when something breaks. DIY is rational only for static sites or if your time is genuinely worth less than $30-50/hr.
Three reasons: (1) Hosting costs more — Vercel/Netlify start higher than shared WordPress hosting; (2) Updates require dev work — you can't click "update plugin" on a custom Next.js stack; (3) Security patching is on you — no Wordfence/Sucuri equivalent. Custom React makes sense for high-traffic SaaS or sites with serious performance requirements; for content sites, WordPress is usually 2-3× cheaper to run.
Standard maintenance: hosting, backups, security patching, plugin updates, uptime monitoring, light content updates. NOT included: redesigns, new feature builds, SEO content production, ad campaign management, custom integrations. Those are project-based or higher-tier retainers. Watch for agencies that rope in "minor content updates ≤2hr/mo" — most clients exceed this in month 2.
They're not hidden in the sense of being secret — they're hidden in the sense that most maintenance calculators (and many vendor proposals) leave them out, then surprise you when the invoice arrives. Ahrefs alone runs $99-199/mo for serious SEO work. Cloudflare Pro is $20/mo. Premium WordPress plugins easily total $300-1000/yr. Add them upfront so you're not surprised.
For static sites and small Jamstack: yes, the free tiers cover most use cases. For WordPress: no — you need real hosting (WP Engine, Kinsta, SiteGround). For Shopify: it's hosted, you just pay the platform fee. For custom React with auth + DB: free tiers work until you hit traffic, then prices climb. Run our actual hosting cost separately if your traffic is >50K visitors/mo.
Sources: WP Buffs · Maintainn · SiteCare · GoDaddy Pro · WP Engine · Kinsta · Shopify Partners · Webflow · Vercel · Cloudflare · Clutch 2024 · GoodFirms 2024