CapGains.io - Interactive Capital Gains Calculator & Tax Report Generator
A web application where users input their brokerage transactions (buy date, sell date, cost basis, proceeds), and the system automatically calculates short-term vs. long-term gains, applies wash-sale rules, handles specific lot identification, and generates a clean IRS Form 8949 + Schedule D ready to attach to their tax return. Users can upload CSV exports from their brokers (Fidelity, E*TRADE, Robinhood, etc.) or manually enter trades.
25 weeks • 70% confidence
Value Proposition
Eliminates guesswork by automating the most error-prone part of tax prep (gain/loss calculation and form population). Cheaper than an accountant ($15–50/year vs. $300–1000), faster than manual spreadsheets, and produces audit-defensible documentation. Brokers don't calculate tax liability; tax software is generic. This bridges that gap with brokerage-specific logic.
Target Audience
Individual investors and active traders (especially those with 10+ annual trades across multiple accounts); self-directed retirement account holders; people earning W-2 income + side investment income who can't justify $500+ accountant fees
Key Features
- Brokerage CSV import parser (auto-detects format from Fidelity, Schwab, Interactive Brokers, etc.)
- Wash-sale rule detection and adjustment engine
- Specific lot identification tool (FIFO, LIFO, average cost, highest cost)
- And more, with full implementation detail...
Tech Stack
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Sign up freeOriginal Problem
Individuals struggle to accurately calculate and report capital gains taxes, leading to costly mistakes and audit riskIndividual investors and traders lack clear guidance on how to properly calculate capital gains tax liability across multiple transactions, holding periods, and account types. Current solutions are fragmented—tax software is generic, accountants are expensive, and IRS guidance is dense—leaving people confused about whether they owe taxes, how much, and how to report it correctly. This confusion causes either underpayment (audit risk) or overpayment (wasted money).
Score: 21.4% • 1 demand signal