Estimate the deposit, mortgage payment, rent on the unsold share and total monthly cost of a shared ownership home.
Estimate your shared ownership costs
Shared ownership shares are commonly 25% to 75%; some homes allow 10%.
Estimated shared ownership result
| Landlord’s remaining share value | |
|---|---|
| Annual rent on remaining share | |
| Monthly service, ground and other costs | |
| Estimated cash needed upfront | |
| Mortgage interest paid over full term |
The result excludes Stamp Duty Land Tax and future changes to rent, service charges, mortgage rates or the property’s value.
How shared ownership works
Shared ownership lets an eligible buyer purchase part of a home and pay rent to a landlord on the remaining share. GOV.UK says buyers generally purchase between 25% and 75% of the market value, although some homes allow a 10% share. The deposit is usually calculated against the share being purchased rather than the full property value.
The calculator follows the current GOV.UK shared ownership guidance. Different arrangements apply in Scotland, Wales and Northern Ireland, so this estimate is aimed at the England scheme.
How the calculator works
The mortgage result uses a standard capital-and-interest repayment formula with equal monthly payments. Service charges, ground rent and other monthly costs are then added to the estimated mortgage payment and rent.
Typical shared ownership inputs
| Input | What it represents |
|---|---|
| Full market value | The value of 100% of the property |
| Share percentage | The part you are buying |
| Deposit percentage | The cash deposit against your purchased share |
| Rent rate | The annual percentage charged on the landlord’s share |
| Service charge | Leasehold and communal costs quoted by the provider |
Shared ownership rent
You pay rent on the part you do not own. For a new-build shared ownership home, GOV.UK states that the first-year rent limit is 3% of the landlord’s share and most landlords charge 2.75%. Resale homes can begin with the rent paid by the previous shared owner. Use the exact rate and charge from the key information document or lease.
Rent is normally reviewed annually and can increase. The calculator shows the first-year monthly rent only; it does not forecast lease-based increases.
Worked example
For a £300,000 home with a 40% share, the purchased share costs £120,000. A 10% deposit on that share is £12,000, leaving a £108,000 mortgage. The remaining 60% is worth £180,000, so rent at 2.75% is £4,950 a year or £412.50 a month. Mortgage payments and entered charges are added to this rent.
Costs the estimate may not include
Budget separately for Stamp Duty Land Tax, reservation fees, conveyancing, surveys, mortgage fees, removals, insurance, repairs and future service-charge changes. Shared ownership homes are leasehold properties, and the buyer may be responsible for repair costs even while owning only part of the home.
The landlord’s affordability assessment and the mortgage lender’s checks determine whether the purchase is affordable. A low initial deposit does not guarantee mortgage approval.
Staircasing
Buying additional shares later is called staircasing. As your share increases, rent is charged on a smaller landlord share. The price of a future share normally depends on the property’s value at that time and can require a valuation, legal work and an administration fee.
Related UK calculators
Compare a standard mortgage with the United Kingdom Mortgage Calculator. Landlords can estimate investment borrowing with the Buy-to-Let Mortgage Calculator. Council tenants can compare an alternative purchase route using the Right to Buy Calculator.
Browse more property tools on the United Kingdom Calculator homepage.
Frequently asked questions
What share can I buy?
Most shared ownership purchases are between 25% and 75% of the home’s value, while some homes allow an initial 10% share.
Is the deposit based on the whole property?
Usually no. The deposit is generally based on the value of the share you are purchasing.
How is shared ownership rent calculated?
It is generally an annual percentage of the value of the share retained by the landlord.
Does the monthly result include service charges?
Yes, if you enter them. It also includes entered ground rent, estate charges and other monthly housing costs.
Does this calculator include Stamp Duty?
No. Shared ownership Stamp Duty choices and circumstances differ, so obtain a calculation from your solicitor or HMRC guidance.