Minimum Rent Needed
While the break-even calculator focuses on existing costs, this calculator works backwards from a target investment to tell you the minimum rent required for any given property to be financially viable. Enter the purchase price, deposit, mortgage rate, and target profit, and it tells you the minimum rent you need to achieve. Compare this against achievable market rent to quickly assess whether a deal makes sense.
Why this matters
Rather than hoping a property's rent will cover costs, minimum rent needed turns the analysis around: it tells you what rent you need and lets you check whether the market will support it — before you commit.
Key points
- Always check minimum rent needed against local market rent before making an offer
- A gap between minimum needed and achievable rent is the most common reason deals fall through
- At high LTVs and interest rates, minimum rent may exceed market achievable rent
- Building in a target profit above minimum viable makes the investment more resilient
- Consider future rate rises: model break-even at a rate 1–2% higher than today's
- Lenders run their own affordability test — your minimum rent and the lender's minimum may differ
Frequently asked questions
How is minimum rent needed different from break-even rent?
Break-even rent calculates the minimum given your existing costs. Minimum rent needed works backwards from a proposed purchase price and mortgage terms to tell you the required rent before any purchase decision. It is a planning tool; break-even is a monitoring tool.
What LTV should I use when calculating minimum rent needed?
Model your intended LTV and also test a more conservative LTV (e.g. if you plan 75%, also model 80%). Lenders sometimes change criteria between offer and completion. Also model the rent needed at a rate 1% higher to test resilience.
Should I include target profit in the minimum rent calculation?
Yes — a property that breaks even at minimum rent but no more is very fragile. Unexpected costs, rate rises, or void periods will push it into loss. Add a minimum profit margin of £100–£200/month to create a meaningful buffer.
What if the minimum rent exceeds local market rates?
This means the deal is unlikely to be financially viable at the proposed purchase price, LTV, or rate. Options include: negotiate the purchase price down, increase the deposit to lower the mortgage, find a lower rate, or accept lower profitability if capital growth is compelling.