Bridging Loan Calculators

The core cost calculator shows four things: the retained interest, the arrangement fee, the net advance, and the equivalent APRC. The net advance is the figure that matters most in practice. It is the amount that will actually be transferred to you, after the lender deducts the full interest charge for the planned term and the arrangement fee from the gross loan upfront. This is how retained interest bridging works: because no monthly payments are made, the lender takes the interest cost at the start rather than collecting it over time.

The gap between gross loan and net advance is not a hidden charge. It is simply the mechanics of how bridging interest is structured. If your transaction requires a minimum amount to complete, you need to set the gross loan high enough that the net advance, after all deductions, still covers that figure. Adjusting the gross loan slider upwards while watching the net advance figure is the most practical way to use the calculator for that purpose. For development projects where funds are released in stages, our guide to bridging loan staged drawdowns explains how the calculation changes in that structure.

The LTV calculator takes three inputs: the assessed value of the security property, any existing first charge mortgage outstanding against it, and the bridging loan required. It combines the mortgage balance and the bridging loan, divides the total by the property value, and shows the combined LTV percentage alongside a set of illustrative lender appetite bands. This is the figure a bridging underwriter calculates first, because it determines how much security headroom the lender has if the loan cannot be repaid and the property needs to be sold.

Most bridging lenders will consider cases up to 70 to 75% combined LTV on a standard residential property with a credible exit strategy. Above 75% the pool of available lenders narrows noticeably. The calculator also shows the headroom remaining below a 70% LTV cap in pound terms, which is often more useful than the percentage alone when working out whether the deal has room to move. The bands shown are illustrative — actual lender appetite varies by property type, exit strategy and borrower profile. Our guide to understanding loan-to-value ratios covers how lenders apply LTV criteria in practice.

Two things drive the difference. The first is compounding: each month's interest is calculated on the outstanding balance, which on a retained interest bridging loan is the full gross loan throughout the term. Simple multiplication of the monthly rate by 12 ignores this. The second is the arrangement fee: because the fee is deducted upfront from the gross loan, it effectively increases the cost of borrowing relative to the funds actually received, and the APRC calculation captures this while the monthly rate alone does not.

The converter shows both figures side by side alongside a breakdown of how much of the difference comes from compounding and how much from the fee. This is most useful when comparing a bridging product against a second charge mortgage or other annual-rate borrowing, because it puts both on the same footing. The APRC figure will always look high relative to the headline monthly rate, which is why bridging is typically assessed on monthly rate and net advance in practice. For a broader comparison of how bridging sits against other secured borrowing options, our guide to bridging vs other short-term funding options is worth reading alongside this tool.

The cost of delay calculator models what happens to your bridging costs if your exit takes longer than planned. It compares the retained interest, arrangement fee, total cost and net advance under your planned term against the same figures with an extension applied. The key outputs are the additional interest cost of the extension and the resulting reduction in net advance. The per-month and per-day cost figures make the impact of a delay concrete: if each additional month costs £2,250 in retained interest, a three-month contractor overrun has a specific, quantifiable effect on margin.

The most practical way to use this calculator is to run your base case first, then apply a one or two month extension to see how much contingency your numbers need to absorb before the deal stops working. Note that the calculator models retained interest only. Some lenders also charge a separate extension fee of 0.5 to 1% of the gross loan when a term is formally extended, which would add to the figures shown. Our article on what commonly delays refurbishment completions is useful context for understanding which scenarios are worth stress-testing, and our guide to extensions vs refinancing covers the options if an extension is not straightforward.

The auction finance timeline maps the typical sequencing of a bridging loan completion following an auction purchase, across the three workstreams that need to progress at the same time: the finance track, the legal track, and the valuation. Each track is shown as a bar across a 28-day window, reflecting the standard completion deadline for auction purchases. Clicking any stage opens a panel showing what happens during that stage, what typically causes delays, and what can be done to prevent them.

The three tracks must run in parallel because the 28-day window does not allow for sequential working. If any track waits for another to finish first, the timeline collapses. The valuation cannot wait until finance is approved. Legal work cannot wait until the valuation is returned. The timeline makes this visible and shows where the most common pinch points occur. Valuation access and legal pack quality are the two factors that derail the most cases. Our auction bridging checklist covers what to have in place before bidding, and our guide to how auction legal packs affect bridging explains what solicitors need to review and why it matters.

The calculators are designed to work in sequence as well as independently. For most borrowers, the logical starting point is the LTV calculator, which confirms whether the proposed borrowing falls within typical lender appetite before any cost modelling takes place. Once LTV is confirmed, the core cost calculator shows the net advance and APRC for the planned term. The APRC converter can then be used to compare that annualised cost against alternative borrowing options if that comparison is relevant.

For development or refurbishment projects, the cost of delay calculator should be run as a second pass after the core cost calculator, using a one or two month extension scenario to stress-test the appraisal. For auction buyers, the LTV calculator and auction timeline are the two most time-sensitive tools, since both speak directly to whether the deal is fundable and whether completion within 28 days is realistic. All figures produced are illustrative and are not a substitute for a personalised illustration from a lender or broker. Our guide to comparing bridging loan quotes properly explains what a formal illustration should include and how to compare offers on a like-for-like basis.