Drift — current weight = value / total; drift = current weight − target weight, in percentage points.
Trades — the new total is current total + new cash. Each position's trade = target% × new total − current value. Positive = buy, negative = sell. Trades always sum to exactly the new cash (or $0 when no cash is added).
Target normalization — if your targets don't add to 100%, the calculator scales them proportionally and flags it, so the trade list always allocates the full portfolio.
Turnover — total dollars traded (excluding new-cash buys) as a share of the portfolio; a proxy for the tax and cost impact of the rebalance.
What this omits — taxes on realized gains, lot selection, trading costs, fractional-share constraints, and drift bands (rebalance-when-5%-off rules). Sells in taxable accounts can trigger capital gains; adding new cash to underweights is usually the tax-friendlier path.