Shared ownership calculator
Shared ownership lets you buy a share of a home and pay rent on the rest. This calculator shows the full monthly cost — mortgage, rent and service charge combined — so you can compare it like-for-like with renting or buying outright.
Most schemes allow 10–75%
Typically 5–10% of the share you're buying
Usually 2.75% of the landlord's share, charged annually
Estimated total monthly housing cost
£1,299
Mortgage + rent + service charge
Share value
£140,000
Mortgage amount
£130,000
Monthly mortgage
£698
Monthly rent
£481
Service charge
£120
Landlord's share value
£210,000
Estimate based on the values entered. Rent and service charges can rise, and the rent review formula depends on your lease: newer shared ownership leases generally use CPI + 1%, while older leases may use RPI + 0.5%. Check your own lease and current service-charge information. You can buy further shares over time ("staircasing") to reduce or eliminate the rent. Doesn't include buildings insurance, ground rent or any leasehold-specific charges.
How shared ownership works
You buy a share (typically 10–75%) of the property and pay a subsidised rent on the share you don't own. Your deposit is calculated against the share you're buying — not the full property price — which can dramatically reduce the cash needed to get on the ladder.
Things to plan for
- Staircasing — you can buy further shares over time, reducing the rent portion. The permitted share sizes depend on your lease: purchases are commonly 10% or more, some newer leases allow 5%, and some homes bought from 1 April 2021 allow an additional 1% purchase each year for the first 15 years.
- Rent reviews — rent can rise and the review formula depends on your lease. Newer leases generally use CPI + 1%; older leases may use RPI + 0.5%.
- Service charge — applies to most shared ownership homes and can rise faster than rent.
- Selling — there are specific rules and the landlord often has a nomination period to find a buyer first.
- Lender choice — only a subset of lenders accept shared ownership cases, which is where a broker helps.
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