11 free calculators for marketers, affiliates and store owners: ROAS + break-even ROAS, CPM/CPC/CPA, max CPA, affiliate EPC, LTV:CAC, margin vs. markup, UTM builder, SERP preview and A/B significance. No signup, everything runs in your browser (even the CSV tool), and each result comes with the formula, benchmarks and what the number means for your business.