The equal monthly draw model used in the HELOC repayment calculator is a useful approximation, but most borrowers do not draw evenly. A builder is paid at each project stage. School fees are drawn termly. A deposit draw happens on a single date. This planner lets the borrower enter up to six specific draws with their timing to see the actual payment profile, the interest cost during the draw period, and the saving compared with drawing the full amount on day one. All figures are illustrative only.
At a Glance
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Enter up to six planned draws with their month and amount. The tool calculates the interest-only payment at each stage, the total interest, and the saving compared with drawing the full amount on day one.
During the draw period, payments are interest-only on the drawn balance. Each new draw increases the balance and the interest-only payment steps up accordingly. When the draw period ends, the outstanding balance converts to capital-plus-interest repayments over the remaining term and the monthly payment increases. The payment profile chart shows this pattern visually.
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The interest saving depends on how the draws are spread. Front-loaded draws (most of the money drawn early) save less than evenly spread draws, because the average balance is closer to the total for most of the period.
A home improvement project where most of the budget is spent in the first three months produces a smaller saving than school fees drawn termly over five years. This planner shows the actual saving for the specific draw schedule entered, rather than a generic estimate based on equal monthly draws.
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During the draw period, the borrower pays interest only on the drawn balance. When the draw period ends, the balance converts to capital-plus-interest over the remaining term.
This two-phase structure means the interest-only payment builds as each draw increases the balance, then jumps to a higher capital-plus-interest level when the draw period ends. The planner shows both phases. Borrowers should budget for the repayment-period payment (the highest figure), not the draw-period payment. The guide to what is a HELOC covers the full two-phase lifecycle.
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This tool excludes fees. Lender fees and broker fees add to the total cost and should be factored into any product comparison.
The figures shown are interest and capital repayment only. The guide to HELOC fees and costs covers the full fee breakdown including the impact of adding fees to the balance.
Draw period planner
Enter your planned draws to see the payment profile and interest saving. Illustrative only.
Planned draws (up to 6)
All figures are illustrative and simplified. Interest-only payments during the draw period, capital-plus-interest during the repayment period, reflecting UK HELOC product structure. Fees (lender product fee, arrangement fee, and broker fee) are excluded. This planner does not constitute a quote, offer, or financial advice.
About this tool
What it calculates
Payment profile and interest cost for a specific draw schedule
Enter the month and amount for each planned draw. The tool calculates the interest-only payment at each stage (building as each draw increases the balance), the total interest over the full term, the interest cost during the draw period alone, and the saving compared with drawing the full amount on day one. When the draw period ends, the balance converts to capital-plus-interest over the remaining term.
How it differs from the repayment calculator
Specific draws instead of equal monthly assumptions
The HELOC repayment calculator models equal monthly draws spread evenly over the draw period, which is a useful approximation. This planner lets the borrower enter the actual draw schedule, which produces a more accurate estimate for project-specific or termly spending patterns.
How to use this planner
Set the rate, draw period, and total term
Use the sliders to set the illustrative interest rate, the draw period length (two to five years), and the total term (five to thirty years). The guide to HELOC rates in the UK includes illustrative rate bands by LTV tier if you are unsure which rate to use.
Enter your planned draws
For each draw, enter the month number (within the draw period) and the amount. The default shows a four-draw home improvement schedule. Clear the rows and enter your own figures for a personalised calculation. Leave unused rows empty. For school fees, enter each term’s draw (for example, month 1, month 5, month 9 for the first year’s three terms).
Read the comparison
The left panel shows the result for your specific draw schedule. The right panel shows what the same total amount would cost if drawn all at once on day one (interest-only during the draw period, then capital-plus-interest during the repayment period). The saving figure shows the interest difference between the two. The payment profile chart shows how the interest-only payment builds with each draw, then increases when the repayment period begins.
Understanding the results
The saving from a specific draw schedule depends on two factors: how much of the total is drawn early versus late, and how long the gap is between the first and last draw. A draw schedule where 80% of the total is drawn in the first two months produces a small saving because the average balance is close to the total for most of the draw period, and the interest-only payments are close to what a full draw would produce. A draw schedule where the total builds gradually over several years produces a large saving because the average balance is well below the total for a sustained period.
The payment profile chart makes this visible. Each time a new draw is made, the interest-only payment steps up because the drawn balance has increased. Between draws, the payment stays flat (because no capital is being repaid during the interest-only phase). When the draw period ends, the payment jumps to the capital-plus-interest level for the repayment period, which is the same regardless of the draw pattern. Borrowers should plan for the repayment-period payment (the highest figure), not the draw-period payment, because that is the long-term commitment. The guide to HELOC eligibility notes that affordability is assessed on the repayment-period payment.
The lump sum comparison panel shows the cost of drawing the full amount on day one from the same HELOC: interest-only on the full balance during the draw period, then capital-plus-interest during the repayment period. If the borrower is comparing a HELOC with a lump-sum product at a different (lower) rate, the HELOC vs lump sum comparator provides that cross-rate comparison.
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Checking won’t harm your credit scoreFrequently asked questions
What draw schedule should I enter for a home improvement project?
Use the builder’s expected payment schedule. Most extension and renovation projects involve four to six stage payments: an initial deposit, a groundworks payment, a structural completion payment, a first-fix payment, a second-fix payment, and a final retention release. The amounts and timing depend on the project scope and the builder’s terms. If you do not yet have a detailed schedule, the default values in the tool (four draws over eight months) are a reasonable starting point for a typical extension project.
The guide to using a HELOC for home improvements covers how phased drawdown works for different project types. The project budget builder can help estimate the total cost and likely phasing before committing to a facility amount.
Building a 10% to 15% contingency into the total is worth considering, but the contingency does not need to be entered as a separate draw in the planner. It represents capacity that is available if needed, not a planned spend. The planner models the planned draws, and any undrawn contingency carries no interest cost.
What draw schedule should I enter for school fees?
School fees are paid three times per year, typically in September, January, and April. For a five-year school career, this means fifteen draws. The planner supports up to six draws, so enter the first year’s three termly draws to see the year-one payment profile, or enter one annual draw per year (five draws for a five-year career) to see the overall pattern. The annual approach is less precise but captures the cumulative effect across the full draw period.
For a detailed worked example of school fee funding with year-by-year figures, the guide to using a HELOC for school fees covers the full Phase 1 and Phase 2 planning framework. That guide uses a seven-year secondary career as its worked example and includes the total cost picture with fees and interest.
If the school offers a discount for paying the full year’s fees in advance (some offer 1% to 3%), the planner can model the annual draw pattern (one larger draw per year) versus the termly pattern (three smaller draws per year) to see which produces lower total interest. At typical HELOC rates, the interest saving from termly draws usually exceeds a discount below 2%.
Why is the saving smaller when most of the money is drawn early?
The saving comes from carrying a lower average balance than the full amount during the interest-only draw period. If most of the money is drawn in the first few months, the average balance is close to the total for most of the draw period, and the interest-only cost is close to what a lump sum would produce. The saving is concentrated in the brief period before the large draws happen, which may only be a few weeks or months of lower interest.
Conversely, when draws are spread evenly across the draw period, the average balance during the draw period is roughly half the total, and the interest saving is substantial. This is why school fee funding (termly draws over five years) produces a larger saving than a typical home improvement project (most of the budget spent in the first eight months).
The planner makes this trade-off visible. A borrower who is considering whether to stagger project payments more evenly (paying the builder in more, smaller stages) can enter different schedules and compare the interest cost. Even a modest rearrangement of the timing can save several hundred pounds over the draw period.
Does this tool account for fees?
No. The figures shown are interest and capital repayment only. HELOC fees, including the lender product fee (typically 2.0% to 2.6% of the facility amount, capped), the lender arrangement fee (typically 6.7% to 7.8%, capped at £3,000), and any broker fee (typically 5% to over 10% of the facility amount), are excluded. These fees can be significant and should be factored into any cost comparison.
If fees are added to the loan balance, the borrower pays interest on the fee amount over the remaining term. The guide to HELOC fees and costs includes a worked example showing the impact of adding fees to the balance. For a complete cost picture, the fee total should be added to the interest figures from this planner.
The APRC (annual percentage rate of charge) includes lender fees and provides a more complete comparison than the headline rate. However, broker fees may not be captured in the APRC, so the total cost across different brokers should be compared separately. The guide to APR on secured loans explains how APRC works.
Can I change the draw schedule after the HELOC is set up?
Yes. The draw schedule entered into this planner is for planning purposes only. Once the HELOC facility is live, the borrower can draw any amount at any time during the draw period, up to the facility limit. There is no requirement to follow the planned schedule. If the project takes longer than expected, or if the costs come in higher or lower, the borrower draws as needed rather than according to a fixed plan.
The planner is most useful for estimating the interest cost before committing to the facility, not for locking in a specific draw pattern. If the actual draws differ from the plan (which they usually do), the interest cost will differ proportionally. Drawing later than planned saves interest. Drawing earlier costs more. The underlying mechanics are the same regardless of whether the schedule is followed exactly.
Returning to the planner after the draws have started and entering the actual draw amounts and dates (alongside the remaining planned draws) gives an updated estimate of the total interest cost based on what has actually happened rather than what was originally planned.
Squaring Up
The draw period planner models the actual payment profile and interest cost for a specific draw schedule, rather than relying on the equal monthly draw approximation. During the draw period, payments are interest-only on the drawn balance. When the draw period ends, the balance converts to capital-plus-interest over the remaining term. The saving from staged draws depends on how the draws are spread: front-loaded schedules (most of the budget spent early) produce smaller savings than evenly spread schedules (termly school fees or multi-year draws).
The tool is for planning, not for locking in a commitment. The borrower can draw at any time during the draw period and in any amount up to the facility limit. The planner helps estimate the cost before committing and can be revisited as the actual draw pattern evolves.
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Checking won’t harm your credit score Check eligibilityThis planner is for illustrative purposes only and does not constitute financial advice, a quote, or an offer. Your home may be at risk if you do not keep up repayments on a mortgage or other debt secured against it. The figures shown exclude fees (lender product fee, arrangement fee, and broker fee) which form a material part of the total cost. Interest rates are illustrative; most UK HELOCs carry variable rates that can change during the term. Actual payments and total costs depend on the specific product, rate, fees, drawdown pattern, and individual circumstances.
