GM Calculator is a free, privacy-first collection of 41 online calculators for marketing, finance, health, and math. • Instant results (no page reload) • No sign-up, no ads, no tracking • Tools include ROAS, Compound Interest, BMR, TDEE, Percentage, GPA, Margin & more • Clean, fast, and works perfectly on mobile Whether you're a marketer optimizing ads, planning investments, tracking fitness goals, or solving math problems — get accurate answers in seconds.