Why doesn't it tell me to sell the overweight holding?

Because you asked where to put new money, and because selling is a different decision with different consequences — tax, spreads, and timing. When a contribution can't bring a holding back inside its band, the result says so explicitly rather than quietly recommending a sale.

Do the amounts always add up to what I entered?

Yes, exactly — to the cent. Allocations are computed in whole cents and the largest row absorbs any rounding remainder, so the table's total is always the number you typed.

Why does it only top holdings up to the edge of the band, not to the target?

Because a holding inside its tolerance band is on plan by your own definition. Spending your contribution centring something that was already acceptable would be imposing a stricter plan than the one you set.

Is this a recommendation?

No. It's an example calculation based on the targets you set — arithmetic, not advice. It doesn't know your tax situation, your other accounts, or anything else about you.

Contribution Coach

Rebalancing usually means selling something. If you're adding money anyway, the deposit can do the work instead. Enter an amount and see how it would be split to bring the holdings that have fallen below their target band back toward it — an example calculation from targets you set, never a recommendation to buy or sell.

Educational use only — not investment advice. Results are hypothetical.Read full disclaimer

This tool is for educational and informational purposes only and does not provide financial, investment, tax, legal, or accounting advice. Results are hypothetical and based on historical data and assumptions that may be inaccurate. Past performance does not guarantee future results. Consult a licensed professional before making investment decisions.

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What is the Contribution Coach?

Enter an amount and see how it would be split across your holdings — filling the underweight ones back toward their target bands first, then spreading the remainder across your plan. It never suggests selling anything.

New here? What you'll get

Where should the next $500 go? — A 60/40 plan that has drifted to 68/32 after a stock run-up — see how a contribution is split to bring it back toward the bands without selling anything.

Start below ↓

New here? How this works

Most rebalancing advice assumes you're willing to sell, which means tax, spreads and a decision you may not want to make. If you're adding money anyway, the deposit can do the work instead. Contribution Coach takes the target weights and tolerance bands from your Portfolio Plan, works out which holdings have fallen below their band, and allocates your contribution in proportion to those gaps until the bands are restored — then spreads anything left over across your targets pro-rata. The allocations always add up to exactly the amount you entered, and no holding is ever assigned a negative amount: this is a contribution calculator, not a trade list. It also says plainly when a contribution cannot fix the problem, which happens whenever a holding is overweight — only selling or a much larger deposit brings that one down.

How to use it

1Set a Plan on a saved portfolio: target weights, a tolerance band, and what the portfolio is worth today.
2Enter the amount you're about to add.
3Read the split — the underweight holdings come first, and the table shows each holding's share before and after.

What you'll get

How much of the contribution goes to each holding
Each holding's share of the portfolio before and after
How much closed a band gap vs. how much spread across your targets
Which holdings a contribution alone can't bring back inside the band

↓ Start below

A sample plan: 60% VTI / 40% BND with a ±5pp tolerance band, which has drifted to 68 / 32 after a stock run-up. Change the numbers and watch the split change.

Amount to addPortfolio valueTolerance band (pp)

Of 500, the largest share (500) goes to BND. BND, VTI stay outside the ±5pp band — a contribution can bring an underweight holding up, but it can't bring an overweight one down.

Where a $500 contribution would go under your plan's targets, with each holding's share before and after.
Holding	Now	Target	Add	After
BNDstill outside the band	32.0%	40.0%	$500	32.3%
VTIstill outside the band	68.0%	60.0%	—	67.7%
Total			$500

$500 closes the gap back to your ±5pp bands; $0 spreads across your targets. This is an example calculation based on the targets you set — not investment advice or a recommendation.

This runs on sample numbers, free and with no account. Running it on your own portfolio and plan is part of Pro — see plans. A free account gets you the Plan itself, and a monthly Portfolio Check-in measured against it.

How the Contribution Coach works

Current weights are rescaled to 100% so a rounded holdings list isn't read as a universal shortfall. Each target's shortfall is measured to the LOWER EDGE of its tolerance band — not to the target itself, since a holding inside its band is on plan by your own definition — against the portfolio total after the contribution. The contribution is allocated across those shortfalls in proportion to their size until they are closed, and any remainder is spread across the targets pro-rata. Allocations are computed in whole cents and the largest row absorbs the rounding remainder, so the rows sum to exactly the amount entered. Nothing is ever allocated a negative amount, so no output is ever a sale.

Full methodology — formulas, data sources & limitations ↗

FAQ

Why doesn't it tell me to sell the overweight holding?: Because you asked where to put new money, and because selling is a different decision with different consequences — tax, spreads, and timing. When a contribution can't bring a holding back inside its band, the result says so explicitly rather than quietly recommending a sale.
Do the amounts always add up to what I entered?: Yes, exactly — to the cent. Allocations are computed in whole cents and the largest row absorbs any rounding remainder, so the table's total is always the number you typed.
Why does it only top holdings up to the edge of the band, not to the target?: Because a holding inside its tolerance band is on plan by your own definition. Spending your contribution centring something that was already acceptable would be imposing a stricter plan than the one you set.
Is this a recommendation?: No. It's an example calculation based on the targets you set — arithmetic, not advice. It doesn't know your tax situation, your other accounts, or anything else about you.