Buying a House Together Calculator
Buying with a friend, family or a partner? See who owns what, the loan, and each person's repayments.
Going in on a property with someone else - a friend, a sibling, a partner - starts with a question that is surprisingly easy to get wrong: who actually owns what, and who pays what? This free calculator takes each person's deposit (down payment) and the purchase price and works out everyone's ownership share, the loan you need, and each person's slice of the repayments.
It is built for 2 to 6 co-buyers and uses the same contribution math Laddered uses when people set up a property together - so the split you see here is the split you would actually run.
How this calculator works
- Enter the purchase price and what each person is putting in. Ownership is split by each person's share of the total deposit - put in 60% of the deposit and you own 60%, held as tenants in common (a tenancy in common, or TIC, in the US).
- The loan is the price minus the total deposit, and the calculator estimates the monthly repayment (principal and interest) from a rate and term you can change. Each share of the loan and the repayment follows the ownership split.
- The percentages are reconciled to total exactly 100%, and every figure is an estimate to get you aligned - not a loan quote.
A worked example
Alex and Sam buy a $800,000 place. Alex puts in $120,000 and Sam $80,000 - a $200,000 deposit - so they borrow $600,000 (a 75% loan-to-value ratio). Alex owns 60% and Sam 40%.
At 6% over 30 years the repayment is roughly $3,600 a month. Split by ownership, Alex covers about $2,160 and Sam about $1,440. Change the price, deposits, rate or term and every number updates.
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
- Ownership is split by each person's share of the deposit; the loan and repayments follow that same split.
- The repayment is an estimated principal-and-interest figure from the rate and term you enter - not a lender quote, and it excludes fees, insurance and rate changes.
- Educational estimate - not legal, tax, credit or financial advice.
Frequently asked questions
How is ownership split when you buy a house together?
A common, fair approach is to split ownership by each person's share of the deposit and hold the title as tenants in common (tenancy in common in the US) so the shares are recorded. This tool does that; you can also agree a different split in a co-ownership agreement.
Are we each responsible for the whole loan, or just our share?
For a joint mortgage you are each usually liable for the ENTIRE loan, not just your percentage - if one person cannot pay, the lender can pursue the other for the full amount. That is why co-buyers put the contribution and exit rules in writing up front.
Does this work for buying in Australia and the US?
Yes. The ownership and loan math is the same. The words differ - deposit versus down payment, tenants in common versus TIC, stamp duty versus closing costs - and those country details are in the Australian and US guides linked on this page.
How should we split the mortgage repayments?
Many co-buyers split repayments in line with ownership, so a 60% owner pays 60% of the repayment. Some split differently (for example if one person lives there); whatever you choose, put it in your agreement so it is clear.
What if one of us puts in more later?
Then ownership can shift over time. This tool captures the starting point from the deposit; if contributions change, a co-ownership agreement (and a tool like Laddered) can track how ownership moves.