Notes

Notes

Explainers that add something the calculator page does not already say: GST 2.0 slabs, old vs new regime, CTC vs Form 16, how to read an IFSC, and what “runs in the browser” actually means. Each one links back to a tool. Stub notes are kept off this list until they are written properly.

GST & invoices

• GST 2.0 Rates Explained — what 5%, 18%, and 40% actually cover

  GST 2.0 after the 56th Council: merit 5%, standard 18%, peak 40%, and why legacy 12%/28% still appear on debit notes. Linked to the free browser GST calculator.

• CGST + SGST vs IGST — how one GST invoice should print

  Place of supply decides CGST/SGST versus IGST — not your warehouse city. Same 18% can split half-and-half or sit entirely in IGST. With worked e-commerce examples.

Tax & salary

• Old vs New Tax Regime India — compare a CTC without signup

  Side-by-side old vs new regime thinking for salaried India in FY 2026–27. Linked to the free in-browser salary calculator — no email wall.

• Standard Deduction ₹75,000 and Section 87A Rebate (FY 2026–27)

  New regime FY 2026–27: ₹75,000 standard deduction, 87A rebate up to ₹12 lakh taxable income, ₹60,000 cap. Approximate, not CA advice — with calculator link.

• CTC vs In-Hand vs Form 16 — three numbers recruiters blur

  How CTC, monthly in-hand, and Form 16 Part B disagree, and how to argue with an offer letter using a local salary calculator.

Banking & IDs

• How to Read an IFSC Code Before You Hit Send

  Bank code, the conventional zero, branch code, and why a valid IFSC with the wrong account still loses money. Linked to the IFSC finder.

• Aadhaar Checksum Is Not KYC — stop pasting 12 digits into random sites

  A Verhoeff check-digit pass only means the digits agree with each other. UIDAI issues numbers. Phishing, VID, and when a local typo check is enough.

Investing

• SIP vs Lump Sum — when inflation is not zero

  Rupee cost averaging helps humans keep investing; lump sum often wins on a rising chart. Toggle inflation so the corpus is not a poster number. Free SIP calculator linked.

Privacy & how we build

• What “Runs in the Browser” Does and Does Not Mean

  Calculator math can be local while ads, analytics, and a few library fetches still use the network. How Privy Tools discloses each exception.

• JWT Decoder in Your Tab vs jwt.io — same math, different trust boundary

  Same base64url algebra as jwt.io. The difference is third-party scripts you did not audit. Prefer decoding production-adjacent tokens locally.