Niveshkar - Free, no-signup finance calculators for India

I'm a solo developer in India and got tired of finance calculator sites that gate everything behind signups, bury the actual formula, or quietly use outdated tax rules. So I built Niveshkar: free, no-signup calculators for income tax (old vs new regime, FY26), SIP, EMI, NPS, HRA, capital gains (post-July-2024 rules), gratuity, PPF and FD. Every page shows the formula and the assumptions, and it's a fast zero-JS static site. Building one new calculator + explainer every week. Would genuinely love feedback on which calculators to add next.