List your holdings, what each is worth today and the share of the portfolio you want it to be. The calculator shows each holding's current weight and what to buy or sell to bring it back to target, to the penny. You can rebalance fully, invest new money without selling anything, or take money out by selling only what is above target. It works for any mix: shares, bonds and cash, funds in an ISA or a pension, or a general investment account. Your figures stay on this device unless you save them.
Enter your holdings
One line per holding or asset class, with its value today and its target weight. The target weights must add up to 100%. Leave the value empty for a fund you want to start buying, and give a target of 0% to anything you want to sell completely.
Choose what to do
Rebalance buys and sells so that every holding ends exactly on its target. Invest puts new money in without selling: it goes first to the holding furthest below its target, then to the next ones as they draw level. Withdraw takes money out by selling only, starting with the holding furthest above its target. If the amount cannot bring every holding back to its target, the calculator says so and, when you invest, shows how much new money would.
Set a band if you use one
If you only rebalance once a holding has drifted a set number of percentage points from its target, enter that band and the calculator counts the holdings outside it. A holding aimed at 60% with a band of 5 points stays within it anywhere from 55% to 65%.
Check the cost before you trade
Look up your platform's dealing charges for each sale and purchase. Outside an ISA, a sale can make a gain liable to Capital Gains Tax; directing new money to the holdings that are behind keeps sales down. Copy the result, export it as a CSV file or save it to Priostack.
Weight now = value of the holding ÷ value of the portfolio.
Value afterwards = value now + new money invested (or − money withdrawn).
Target amount = value afterwards × target weight.
Rebalance: trade = target amount − value now (positive: buy; negative: sell).
Invest without selling: the new money fills the largest shortfalls first, so the holdings it buys all end the same amount below their target. Withdraw by selling only: the mirror image, from the largest excesses.
Gap = weight − target weight, in percentage points.
Amounts are rounded to the nearest penny, a half penny rounding up. If the rounded target amounts would then add up to more or less than the portfolio, the pennies over or short are settled one per holding, on the holdings closest to the half-penny, so the totals always match.
Example: bringing a 60/30/10 portfolio back on target
You hold £7,000.00 of shares, £2,500.00 of bonds and £500.00 of cash, £10,000.00 in all, against targets of 60%, 30% and 10%. Shares now weigh 70%, 10 points over. A full rebalance sells £1,000.00 of shares and buys £500.00 of bonds and £500.00 of cash. Without selling, £1,000.00 of new money would go £600.00 to bonds and £400.00 to cash and leave shares at 63.64%; it would take £1,666.67 of new money to reach every target without a sale.
