About Tradomaniac

What this is, why it exists, and how to reach the person who builds it.

The short version

Tradomaniac is a small set of free calculators for Indian traders and taxpayers: crypto tax, equity and mutual fund capital gains, F&O and intraday trading tax, brokerage and trading charges, position sizing, returns, F&O payoff, options Greeks and implied volatility, and options max pain. No accounts, no sign-up, and nothing you type into a calculator ever leaves your browser. It's an independent project, not a company.

Why these exist

Most calculators for Indian tax and trading either oversimplify the math or get a detail wrong: the wrong rounding on STT, cess applied to the wrong base, a loss set-off rule that doesn't actually apply to the asset class, a broker's rate that was never checked against anything. Tradomaniac exists to get the actual mechanics right instead of approximating them, and to be upfront about what each calculator does and doesn't cover.

How the numbers are checked

Tax rules: Worked from the actual Income Tax Act sections that apply, Section 115BBH for crypto, Sections 111A and 112A for equity and mutual funds, not copied from another calculator site. Where the rule is genuinely ambiguous, like whether crypto losses net against gains, it's resolved by checking the enacted legislative text, not guessed.
Brokerage rates: Checked against each broker's own published rate card, and re-checked when a broker changes its pricing. Statutory charges such as STT and stamp duty follow the whole-rupee rounding those charges are subject to.
F&O payoff math: Checked by hand against known option-strategy formulas, a single bought call, a spread, a straddle, a futures position, rather than assumed correct because the code looked reasonable.
F&O and intraday tax: The audit thresholds and the speculative-loss rules were checked against the Income Tax Department's published text of Sections 44AB and 73, and the outputs against hand-worked examples including the marginal-relief edge just above the rebate limit. The turnover method follows the ICAI Guidance Note on Tax Audit as described in published professional summaries, not read from the note itself, and the tool covers FY 2025-26 under the 1961 Act only.
Options Greeks and implied volatility: Black-Scholes formulas were checked against a standard textbook reference case (price, Delta, Gamma, Vega and Rho matched), and implied volatility is confirmed by feeding a computed price back in and recovering the original volatility.
Property capital gains: The Cost Inflation Index table (2001-02 to 2026-27) was cross-checked across independent published copies of the CBDT notifications, and the 12.5% versus 20% choice was checked against the Income Tax Department's published text of Section 112. Outputs match hand-worked cases, including the 24-month boundary, pre-2001 property and sales before 23 July 2024. Section 50C and exemption eligibility are not modelled.
Expectancy, Kelly and expected move: Formulas were checked against independently computed values, and the losing-streak estimate against a simulation of 20,000 trial sequences.
Advance tax interest: The instalment percentages, the 12% and 36% relaxation, the 1% monthly rate and the 90% test for Sections 234B and 234C were checked against published copies of the statute text, and outputs match hand-worked cases including both edges of the relaxation. The 234A rate and the 234F fee were checked the same way. The capital-gains relief is not modelled.
Risk of ruin, futures and averaging: The risk-of-ruin simulation was compared with a separately written simulation and agrees within sampling error. Futures fair value, basis and rollover cost, and the target-average formula, match independently computed values.
Other assets and leverage: The 12 and 24 month holding periods, the 12.5% rate and the deemed short-term treatment of specified mutual funds and unlisted bonds were checked against the Income Tax Department's published provisions and the Finance Bill 2024 memorandum. The liquidation formula was checked against an exchange's published isolated-margin formula and against a direct equity check on the margin, but real exchanges add fees and tiered margins that it leaves out.
Presumptive (44AD) comparison: The 6% rate, the turnover limits, the five-year rule and the audit link were checked against the Income Tax Department's published text of Sections 44AD and 44AB. Whether F&O trading qualifies for the scheme is described as a judgement to confirm with a professional.
Crypto TDS and ITR form selector: The 1% rate and the Rs 50,000 and Rs 10,000 thresholds of Section 194S were checked against the Income Tax Department's published text. The form selector follows the eligibility rules published on the department's e-filing help pages for assessment year 2026-27, and hedges where a rule is open to professional judgement.
Trade journal and MTF: The journal statistics and the MTF interest and breakeven arithmetic match independently computed values, and the interest method is stated so it can be checked against a broker's own statement.
XIRR: Checked against the worked example in Microsoft's own XIRR documentation (matches to nine decimal places) and against hand-calculated single-investment and SIP cases.
Tax-loss harvesting: Uses the same set-off and rate logic as the Capital Gains calculator, with outputs checked against hand-worked scenarios.
Position size and ROI: Checked against hand-calculated examples, including long and short positions, lot-size rounding, and same-day and negative-return edge cases.
Still evolving: Not everything is verified to the same depth yet. Where a number hasn't been checked against an official source, that's flagged in the calculator's own disclaimer rather than presented with false confidence.

What's inside

Crypto Tax Calculator: FIFO cost-basis matching and flat 30% + 4% cess under Section 115BBH, with exchange import and a Schedule VDA export.
Equity & Mutual Fund Capital Gains: STCG and LTCG under Sections 111A and 112A, with loss set-off, the ₹1.25 lakh LTCG exemption, and the pre-2018 grandfathering clause.
F&O & Intraday Tax Calculator: Business-income tax on futures, options and intraday trading, with the tax audit turnover check, loss set-off and carry-forward, and new versus old regime slab tax.
Stock List Screener: Paste or load a table of stocks, filter it by any number or text column, sort it and download the matches, privately in your browser.
Position Size & Risk/Reward Calculator: Quantity from your capital and risk per trade, with risk/reward ratio and breakeven win rate.
CAGR Calculator: The compound annual growth rate between two values, the end value at a given rate, or the years needed, with doubling time.
P/E Ratio Calculator: P/E, forward P/E, PEG ratio, earnings and dividend yield from a share's price and earnings, and the price a target P/E implies.
Intrinsic Value Calculator: A two-stage discounted cash flow value per share and the Graham number, compared with the price, with a sensitivity table.
ROI / Return Calculator: Absolute, percentage and annualized return on a trade or investment.
Tax-Loss Harvesting Calculator: How much capital gains tax you could save by booking equity losses, and how much long-term gain fits inside the ₹1.25 lakh exemption.
XIRR Calculator: Annualised return on SIPs and other irregular investments and withdrawals, using the same method as the spreadsheet XIRR function.
Property & Land Capital Gains Calculator: Tax on selling land or a building, comparing 12.5% without indexation against 20% with indexation using the Cost Inflation Index.
Trade Expectancy & Kelly Calculator: Expectancy, profit factor, breakeven win rate, expected losing streak, and the Kelly fraction of capital to risk.
Expected Move & Probability Calculator: The price range implied by option volatility and the probability of finishing above or below a level, using Black-Scholes.
Trader Tax Estimator: Every kind of trading and investing income added up, with your total tax under the new and old regimes.
Capital Gains Exemption Calculator (54, 54EC, 54F): How much long-term gain a new house or specified bonds can exempt, the tax left, and the deadlines to invest.
FD Interest Tax & TDS Calculator: Tax and TDS on fixed deposit interest, Form 15G and 15H, and your return after tax and inflation.
Scale-Out & Trailing Stop Planner: Plan staged profit-taking and a trailing stop, with the profit in every scenario and the average exit.
Old vs New Tax Regime Calculator: Compare tax under both regimes with HRA, 80C, 80D, NPS and home loan interest, and find the break-even deductions.
HRA Exemption Calculator: Tax-free house rent allowance using the lowest-of-three rule, for metro and non-metro cities.
Share Buyback Tax Calculator: Tax on shares tendered in a buyback: capital gains from 1 April 2026, or dividend before that.
Dividend Income Tax & TDS Calculator: TDS and slab-rate tax on dividends from each company, with the Rs 10,000 threshold.
SIP & Lumpsum Calculator: Growth of a monthly SIP or lumpsum with a yearly step-up and the value in today's money.
SWP & Retirement Corpus Calculator: How long a corpus lasts with monthly withdrawals, and the highest starting withdrawal that lasts.
EMI & Loan Prepayment Calculator: Your EMI and total interest, and the interest and time saved by prepaying.
PPF, EPF & NPS Calculator: Maturity value of PPF and EPF, and the NPS corpus, lump sum and pension, with editable rates.
Pivot Points & Fibonacci Calculator: Classic, Fibonacci and Camarilla pivot levels and Fibonacci retracements.
Crypto DCA & Profit Calculator: Crypto average cost, break-even, 30% tax and 1% TDS if you sold now, and DCA against a single purchase.
Impermanent Loss Calculator: Impermanent loss for a 50/50 crypto liquidity pool against holding, and whether fees cover it.
Option Theta Decay Planner: Day-by-day option premium decay to expiry, weekend cost and theta per lot.
Advance Tax & Interest Calculator: Interest under Sections 234A, 234B and 234C and the 234F late fee, with the instalment schedule for regular and presumptive taxpayers.
Stock Average Calculator: Your average buy price across purchases, or how many shares to buy to bring it to a target.
Drawdown & Risk of Ruin Calculator: The gain needed to recover from a drawdown, and the simulated chance your account hits a ruin level.
Futures Fair Value & Rollover Cost Calculator: Futures fair value from cost of carry, annualised basis, implied carry and the cost of rolling to the next expiry.
Capital Gains on Gold, Debt Funds & Other Assets: Tax on gold, gold ETFs, debt mutual funds, bonds and unlisted shares, with the holding period and rate for each asset.
Leverage & Liquidation Price Calculator: Liquidation price, distance to liquidation and safe leverage for crypto futures, margin and F&O positions.
Crypto TDS Calculator: The 1% TDS on crypto sales under Section 194S, compared with your crypto tax, with the refund and the drag on your trading capital.
TDS Interest Calculator: Interest on TDS or TCS deducted late at 1% a month or deposited late at 1.5% a month, counted the way TRACES counts months, with the deposit due date for each case.
TDS Late Filing Fee Calculator: The late fee on a TDS or TCS statement at ₹200 a day under Section 234E (Section 427 from April 2026), capped at the tax, and whether the ₹10,000 to ₹1,00,000 penalty could apply.
Which ITR Form?: A short set of questions that tells you whether ITR-1, ITR-2, ITR-3 or ITR-4 applies to your income, and why.
MTF Interest & Breakeven Calculator: The interest on a margin trading facility position, your breakeven price and your return against paying cash.
Trade Journal Analyzer: Win rate, profit factor, streaks, drawdown and an equity curve from your own pasted trade results.
Brokerage & Tax Calculator: Brokerage, STT, exchange charges, stamp duty and GST broken down line by line, across multiple brokers.
F&O P&L Calculator: Multi-leg options and futures payoff across expiry prices, with breakeven, max profit and max loss.
Max Pain Calculator: Strike-wise open interest entry to find the max pain point and Put-Call Ratio for an expiry.
Options Greeks & IV Calculator: Delta, Gamma, Theta, Vega and Rho, implied volatility from an option's market price, or a what-if scenario for a different spot, time and volatility, using Black-Scholes.

Contact

Found a bug, a number that looks wrong, or want a calculator that doesn't exist yet? Email Aayush@astaqc.com. This is a small independent project, not a company with a support team, so response times vary, but every message gets read.

Not tax, legal or investment advice. Every calculator here is a planning tool, not a substitute for a Chartered Accountant or a qualified financial advisor. Confirm anything that affects a real filing or trade with a professional before relying on it.