Stock Tools
Four precision calculators that make the math of being underwater perfectly clear
Average-Down Calculator
Work out your new cost basis and break-even price after averaging down (fees included), with reverse calculation and side-by-side scenarios
Sell-All Calculator
Full breakdown of net profit after selling: commission, stamp tax and transfer fee item by item
Partial-Sell Calculator
Diluted vs break-even cost side by side — understand the cost basis your broker app shows
Break-Even Recovery Table
Down X% — how much upside to get back to even? Generates a shareable chart
What problems do these tools solve?
Retail math is surprisingly hard to pin down: what your cost becomes after averaging down, how much of your proceeds fees eat when you sell, why the cost basis in your broker app differs from what you assumed, how much upside a 30% drawdown needs to break even — every one of these deserves a precise number, not a rough guess. Four calculators cover four decision moments, and every figure can be reconciled item by item with your broker's trade confirmation.
Why set your own fee rates?
Every broker charges a different commission (from 0.01% to 0.03% of turnover), and whether a "5 CNY minimum per trade" applies directly decides how large fees are on small trades. Numbers computed with default rates will not match your trade confirmation. Click "Rates" in the top right, set your actual rates once, and they apply site-wide — stored only on your own device.