Co-owner Buyout Calculator

Work out what one co-owner's share is worth when they exit.

When one co-owner wants out, the others often buy their share. This calculator estimates that buyout from three numbers: what the property is worth now, what is still owed on the mortgage, and the exiting owner's ownership percentage. It is the same net-equity approach Laddered uses when co-owners run an exit.

The result is a starting figure for a fair conversation - the actual price also depends on costs, taxes and what your co-ownership agreement says.

How this calculator works

  • First it works out the property's net equity: current value minus the outstanding mortgage (and any unpaid shared costs, plus or minus adjustments you enter).
  • Then it multiplies that equity by the exiting owner's share. Buyout = net equity times ownership %.
  • If the mortgage is larger than the value, equity is negative - the property is underwater - and the calculator says so rather than showing a meaningless negative payout. In that situation the departing owner may owe money toward the shortfall rather than receive a payout.

A worked example

A property is worth $500,000 with $300,000 still owing, so net equity is $200,000. A co-owner with a 40% share would be bought out for 40% of $200,000 = $80,000.

If that co-owner had also fronted unpaid repairs, you would add those back as an adjustment; if there are selling-style costs to account for, you would subtract them. Small changes to value or debt move the number, which is exactly why it helps to agree the method before anyone wants to leave.

Australia and the United States

The math is the same wherever you buy. For country-specific tax and legal detail - stamp duty and CGT in Australia, closing costs and capital gains in the US - read the guide for Australia or the United States.

Good to know

  • Estimates equity times share; it does not include agent, legal or refinancing fees unless you add them as an adjustment.
  • Does not calculate stamp duty, CGT or US capital gains tax owed.
  • Educational estimate - not legal, tax or financial advice.

Frequently asked questions

How do you calculate a co-owner buyout?

Take the property's current value, subtract what is owed, then multiply that equity by the leaving owner's ownership percentage. This tool does that and lets you add costs or adjustments.

What if we owe more than the property is worth?

That is negative equity. The calculator flags it and, rather than a payout, the exiting owner may need to contribute toward the shortfall. Get advice before acting.

Does a buyout trigger tax or duty?

Often, and it differs by country. In Australia the buyer may pay transfer (stamp) duty on the share acquired and the seller may face capital gains tax; in the US the seller may owe capital gains tax, with the Section 121 exclusion possibly applying. Confirm with a professional - see the Australian and US guides on this page.

How is the property valued for a buyout?

Usually by a professional appraisal or an agreed valuation. This tool uses the value you enter, so use a realistic market figure.

Do we have to refinance to buy someone out?

Generally yes. To release the departing owner from the mortgage, the remaining owners usually refinance the loan into their names, subject to the lender's approval.