Methodology and sources
Kairocal estimates brokerage and statutory charges for Indian markets from a JSON rules engine. The goal is transparent math that is easy to audit against a real contract note. Use the brokerage calculator, compare brokers, or open the charges database.
What is included
- Brokerage (flat, percent, or capped per leg)
- STT (segment-specific buy/sell application)
- Exchange transaction charges (NSE / BSE equity rates)
- SEBI turnover fees
- IPFT (₹10 per crore traded value)
- Stamp duty (buy-side rates by segment)
- DP charges with broker fee, depository fee, per-ISIN, and GST
- GST at 18% on brokerage, exchange, SEBI, IPFT, and DP
- Break-even sell price via binary search
Segments
Equity delivery, equity intraday, MTF, futures, options, commodity, and currency. F&O / commodity / currency use simplified public-rate approximations for exchange and STT. Always confirm with your broker and exchange circulars for live trading.
Broker rules dataset
Version 2026-04-01, effective 2026-04-01. Public schedule approximations for equity cash and simplified F&O/commodity/currency. Verify against current broker tariff sheets before relying for tax filing.
Rules live in src/data/broker-rules.json. Update that file to change schedules without touching engine code. Each broker has an effectiveFrom date for schedule versioning.
DP model
Delivery and MTF sells apply DP. Total DP = per-ISIN rate × ISIN count. Components (broker fee vs depository fee) are stored separately so the ledger can match contract-note style lines. GST on DP is shown as its own line.
Engine separation
All formulas live in src/lib/engine. UI and Zustand store only pass inputs and render results. Unit tests cover equity cash paths and non-negative charges across brokers.
Not included yet
- Live PostgreSQL admin panel and write API for charge edits
- Automated broker-site scraper for tariff updates
- Immutable audit log service for production ops
Those need a backend store. The JSON rules file plus the Charges page act as the current charge database and revision surface.
Disclaimer
Kairocal is an estimation tool. It is not a SEBI-registered platform, tax advisor, or substitute for your broker contract note. Verify figures before trading or filing returns.