Shared Ownership Affordability Calculator
Work out the full monthly cost of shared ownership: the mortgage on your share plus the rent on the share you do not own.
Enter your details below.
How to use
- Enter the full market value of the property and the percentage share you want to buy.
- Enter the rent rate charged on the unowned share (2.75% a year is typical), your deposit, the mortgage rate and term, and your household income.
- Click Calculate Shared Ownership Cost to see the share price, the mortgage, the monthly rent, the total monthly cost and what share of your income that takes.
About this tool
Shared ownership splits a home into two monthly costs: a mortgage on the share you buy and rent on the share you do not own. Enter the full market value, the share to buy, the rent rate on the unowned share (2.75% a year is typical, reviewed annually), your deposit, the mortgage rate and term, and your household income. The tool returns the share price, the mortgage on that share, the monthly mortgage payment, the monthly rent, the total monthly housing cost and what share of your monthly income that takes. Providers look at the total monthly cost against your income and check that the mortgage itself is affordable on its own. The total here excludes any service charge, which is charged separately and should be added to your own budget. You can usually buy more shares later through staircasing, in chunks, until you own 100% in most cases, with each step needing a fresh valuation and affordability check. Estimates only, not financial advice.
Frequently asked questions
How is affordability calculated for shared ownership?
Providers look at the total monthly cost — mortgage plus rent plus service charge — against your income, and check that the mortgage itself is affordable on its own.
What is the rent on the unowned share?
You pay rent to the housing provider on the share you do not own, usually around 2.75% of that share's value per year, reviewed annually.
Can I buy more shares later?
Yes, through staircasing you can buy further shares, usually in chunks, until you own 100% in most cases. Each step needs a fresh valuation and affordability check.
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