Total interest on a loan is usually presented as a lump sum or as part of an APR percentage, neither of which connects naturally to how most people experience spending money. Knowing that a loan costs £1,600 in interest is accurate but abstract. Knowing that the same interest works out to £1.46 per day, roughly the cost of a daily coffee, makes the same figure feel real and comparable to the spending decisions already being made.
This tool calculates the total interest, monthly payment, and daily cost of any loan at any APR and term, then translates the daily figure into everyday spending equivalents. It also shows how the cost changes with a different APR or a different term length, so the value of comparing rates and the trade-off of extending the term are both visible in concrete terms. All figures are illustrative and depend on the inputs you provide.
At a Glance
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The daily cost figure makes total interest tangible by expressing it in the same units as everyday spending.
Total interest divided by the number of days in the loan term gives a per-day figure that can be compared directly against coffees, streaming subscriptions, food shops, or petrol fill-ups. The comparison is not precise, but that is not the point: it gives a human-scale reference for whether the interest cost is large or small relative to the daily spending decisions already being made. A loan that costs the equivalent of half a coffee per day feels different from one that costs the equivalent of a weekly food shop per month, even if the APR comparison between them is only a few percentage points.
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A small difference in APR produces a larger difference in total interest than most people expect over a multi-year term.
The rate sensitivity panel shows the daily cost, monthly payment, and total interest at three percentage points below and above your chosen APR. The compounding effect of a rate difference accumulates month by month across the full term, so a 2 or 3 point difference on a £10,000 loan over three years typically represents several hundred pounds in total interest. Seeing that difference expressed as a daily cost makes the financial case for comparing APRs across providers concrete rather than theoretical.
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A lower monthly payment from a longer term is not the same as a lower monthly payment from a lower rate.
Extending the term reduces the monthly payment but increases total interest, because the balance accrues interest for more months. The term trade-off panel shows both the monthly saving and the total extra interest cost from extending by one year, so the exchange is visible in both directions. The right term is typically the shortest one where the monthly payment is comfortably affordable, because the interest saving from a shorter term is permanent while the higher monthly payment is temporary.
Interactive tool
True daily cost of borrowing
Enter your loan amount, APR, and term to see total interest expressed as a daily cost, compared against everyday spending and shown at different rates and term lengths.
Your data stays private — nothing you enter is stored, transmitted, or accessible to anyone. All calculations run entirely in your browser.
Daily cost of borrowing
£0.00
every day for 3 years
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About this tool
What it calculates
Total interest, monthly payment, and daily cost across your loan
Enter a loan amount, annual percentage rate (APR), and term in years. The tool calculates the monthly payment using the standard annuity formula, the total interest as total payments minus principal, and the daily cost as total interest divided by the number of days in the term. A bar chart shows total interest at every half-year increment from 1 to 7 years at the same APR, with your chosen term highlighted.
Key features
Everyday comparisons, rate and term sensitivity panels, and opportunity cost
Four everyday comparison cards translate the daily cost into familiar spending equivalents. The rate sensitivity panel shows costs at APR minus 3%, current APR, and APR plus 3%. The term trade-off panel compares one year shorter, your chosen term, and one year longer. The repayment equivalent panel shows what the total interest, saved monthly over the term, would accumulate to at 4% and 7% illustrative return.
How to use the true daily cost of borrowing calculator
The tool works best when used with the actual APR of a specific loan you are considering, rather than a round number. The difference between an 8% and a 10% APR on a meaningful loan amount produces a material change in total interest that the daily cost figure makes concrete.
Enter the loan amount, APR, and term
Use the sliders to set the loan amount you are considering borrowing or comparing. Use the annual percentage rate (APR) as stated on any loan illustration or offer document: APR is the standardised cost measure required under FCA rules and is the correct figure to use for comparison. Do not use a monthly rate or a flat rate as these will produce an incorrect total interest figure. Set the term using the slider, which runs from 1 year to 7 years in half-year increments.
Read the headline figures and everyday comparisons
The headline panel shows the monthly payment, total interest, and daily cost. The daily cost is total interest divided by the number of days in the term: it is not a daily charge on the loan but a way of expressing what the total interest amounts to per day over the life of the loan. The four everyday comparison cards below use illustrative unit costs to show what that daily figure equates to in familiar spending terms. All unit costs are labelled as illustrative.
Use the rate sensitivity and term trade-off panels
The rate sensitivity panel shows what the same loan would cost at three percentage points lower and three percentage points higher than your chosen APR, with the current rate highlighted. This makes the financial value of securing a lower rate visible in both daily cost and total interest terms. The term trade-off panel shows the same loan at one year shorter and one year longer, with an insight sentence below explaining the monthly saving from extending the term and the total extra interest that saving costs.
Review the bar chart and the repayment equivalent panel
The bar chart shows total interest at every half-year increment from 1 to 7 years at the current APR, with your chosen term highlighted in full navy. The visual makes the relationship between term length and total interest cost clear across the full range. The repayment equivalent panel shows what the total interest, divided by the term in months and saved as a monthly amount at two return rates, would accumulate to by the end of the loan term.
What the daily cost figure actually means
The daily cost is calculated by dividing the total interest by the number of days in the loan term. It is not a fee charged each day, and it does not reflect how interest accrues on the loan balance, which happens through a monthly compound process applied to the reducing balance. The daily cost is instead a way of expressing the total interest burden in units that are easier to compare against everyday spending decisions. Total interest of £1,800 on a 24-month loan is £2.47 per day. That figure connects the abstract total to something more tangible: whether that daily cost represents good or poor value for the benefit the loan provides is a judgement that depends on the purpose of the borrowing, the alternatives available, and the individual’s financial circumstances.
The everyday comparison cards extend this to specific familiar costs. Seeing that a loan’s daily interest equates to one cup of coffee or four streaming subscriptions per month gives a human-scale reference point that percentages alone do not provide. APR communicates the cost of borrowing accurately for comparison purposes, but it does not immediately convey what the total charge feels like in everyday terms. The daily cost does that conversion, at the cost of some precision, and the comparison cards make it concrete. All unit costs used in the cards are illustrative and are shown alongside the figure they are derived from.
How APR affects the daily cost and total interest
APR has a compounding effect on total interest: a higher rate increases the monthly interest charge on the reducing balance each month, which means a larger fraction of each payment goes toward interest and a smaller fraction reduces the principal. This slows the principal reduction slightly, which in turn means slightly more interest accrues in subsequent months. Over a multi-year term, the combined effect of a rate difference on total interest is typically larger than a simple multiplication of the rate difference by the balance might suggest.
The rate sensitivity panel makes this visible for your specific loan. At a 3 percentage point reduction in APR, the reduction in total interest is shown alongside the daily cost saving and the monthly payment reduction. This is the direct financial value of securing a lower rate, which is why comparing APRs across providers before committing to a loan is worth the time it takes. A 2 or 3 percentage point difference in APR on a £10,000 loan over three years typically represents several hundred pounds in total interest, which translates to a meaningful daily cost difference. The APR on any credit product must be shown on loan illustrations and offers under FCA requirements: comparing APRs across providers is the most reliable way to assess the true cost difference between options. For a broader explanation of how APR is calculated and what it includes, the guide to APR on personal loans covers the mechanics in detail.
The term trade-off: monthly payment versus total cost
Extending the loan term reduces the monthly payment because the same total to be repaid is spread across more months. This makes shorter-term borrowing less affordable on a monthly basis while making longer-term borrowing less expensive per month. The trade-off is that a longer term means more months of interest accruing on the outstanding balance, which increases the total interest paid. The monthly saving from a longer term is real but it comes at a cost in total interest that is also real, and the term trade-off panel in the tool shows both figures side by side so the exchange is explicit.
The insight sentence below the term trade-off cards quantifies this exchange: for example, extending the term by one year reduces the monthly payment by a specific amount but increases total interest by a specific amount. Whether that exchange is worthwhile depends on whether the monthly saving is genuinely needed to make the loan affordable within the household budget, or whether the shorter term is manageable and the lower total interest is worth the higher monthly commitment. There is no universally correct answer: the right term is the shortest one where the monthly payment is comfortably affordable given the full picture of income and outgoings. Using the monthly budget planner alongside this tool helps assess whether a given monthly payment fits within the overall budget.
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All of our calculators and planning tools in one placeFrequently asked questions
How is the daily cost calculated and what does it represent?
The daily cost is calculated as: total interest divided by the number of days in the loan term (term in years multiplied by 365). Total interest is the total amount repaid minus the original principal: total monthly payment multiplied by the number of months, minus the loan amount. The result is the average daily cost of the interest over the full term, expressed as a pound figure per day.
It does not reflect how interest actually accrues on any given day: on a standard repayment loan, interest is calculated monthly on the reducing balance, so the daily interest charge is higher in the early months when the balance is larger and lower in the later months as the principal reduces. The daily cost figure averages this across the full term, which means it is not the charge on any specific day but the average daily burden of the total interest over the life of the loan. It is a way of expressing total interest in a unit that connects more naturally to everyday spending decisions than a lump sum total does.
What is APR and why does the tool use it rather than the interest rate?
APR stands for Annual Percentage Rate. It is a standardised measure of the total cost of borrowing expressed as a yearly rate, and under FCA rules it must include the interest rate and any compulsory fees that form part of the cost of the loan. This makes it the appropriate measure for comparing the true cost of different loan products on a like-for-like basis. A loan with a low headline interest rate but high arrangement fees may have a higher APR than a loan with a slightly higher rate and no fees, and the APR is what captures this difference.
The tool uses APR because it is the figure lenders are required to disclose on loan illustrations, and it is the most reliable input for calculating what a loan will actually cost. For products where the rate is variable, the APR shown is typically the representative APR at the point of illustration, which reflects the rate at or below which the lender reasonably expects at least 51% of credit agreements resulting from the promotion to be made. Your individual rate may be higher if your credit profile means you are offered a higher rate. Always use the actual APR stated on your personal offer rather than the representative figure used in marketing materials when making a specific cost calculation.
How does the repayment equivalent panel work and what is it showing?
The repayment equivalent panel divides the total interest by the number of months in the loan term to produce a monthly equivalent of the interest cost. It then runs a future value calculation on that monthly amount, as if it were saved consistently at two return rates (4% and 7%, both illustrative) over the same number of months. The result shows what the interest cost, if directed as a monthly saving rather than paid as interest, would have accumulated to by the end of the loan term.
This is an opportunity cost frame. It does not imply that borrowing is wrong or that the loan is not worth taking: the purpose of the loan may well justify the interest cost, and in many cases borrowing to achieve a goal sooner outweighs the cost of the interest. The panel exists to make the opportunity cost of borrowing concrete rather than abstract. Knowing that a loan’s total interest, if saved, would have grown to a specific figure is part of the full-cost picture of a borrowing decision. It sits alongside the daily cost, the rate sensitivity, and the term trade-off as a way of understanding what the total cost of the loan represents in different frames.
Does a lower monthly payment always mean a better deal?
No. A lower monthly payment typically results from either a lower interest rate (which reduces both monthly payment and total interest) or a longer term (which reduces monthly payment but increases total interest). These two mechanisms produce very different financial outcomes. A lower monthly payment from a lower rate is straightforwardly better on both measures. A lower monthly payment from a longer term reduces monthly affordability pressure but increases total cost, and whether the trade is worthwhile depends on whether the monthly saving is genuinely needed.
The term trade-off panel in the tool makes this explicit: it shows both the monthly saving and the total extra interest from extending by one year, so the exchange is visible in both directions. For most borrowers, the right term is the shortest one where the monthly payment is comfortably manageable within the full household budget, because the interest saving from a shorter term is real and permanent while the monthly budget pressure from a higher payment is a temporary constraint that resolves when the loan is repaid. Extending the term to reduce monthly pressure is a legitimate choice when genuinely needed, but knowing the total cost of doing so before committing to the longer period is part of making an informed decision.
Can I use this tool to compare two different loan offers?
Yes, and this is one of the most practical uses for it. Run the tool once with the APR and term of the first offer and note the total interest and daily cost. Then run it again with the APR and term of the second offer. The difference in total interest is the financial saving or cost of choosing one over the other. If the two offers have different terms as well as different rates, the total interest comparison captures both effects, since a lower rate over a longer term may produce a higher total interest than a higher rate over a shorter term. The loan offer comparison tool provides a side-by-side view if you prefer to compare two offers at once.
For secured loans, the cost comparison should use the APRC (Annual Percentage Rate of Charge) shown on the European Standardised Information Sheet (ESIS), which includes a broader set of costs than the standard consumer credit APR. For personal loans and other unsecured credit, use the APR on the pre-contract credit information or personal illustration. In either case, use the personalised figure from your offer rather than a representative rate from an advertisement, since the representative APR reflects the rate available to at least 51% of borrowers and your individual rate may differ. Checking eligibility before making formal applications allows you to see indicative personal rates without triggering a hard credit search that could affect your credit file.
Squaring Up
The daily cost figure does one thing: it translates total interest into a unit that connects more naturally to everyday decisions than a lump sum or a percentage does. Whether a loan’s daily cost represents good or poor value for the benefit it provides is not a question the tool answers, because that depends on the purpose of the borrowing, the alternatives available, and the individual’s circumstances. What the tool does is make the cost concrete across multiple frames: per day, per month, over the full term, relative to different rates, and relative to different term lengths.
The rate sensitivity and term trade-off panels are the most actionable parts of the tool for someone comparing specific offers. The difference in total interest between a 9% and an 11% APR on a £15,000 loan over four years is measurable and worth knowing before committing. The daily cost of that difference, expressed in familiar spending terms, makes the financial case for comparing APRs across providers more concrete than a rate comparison in isolation.
Explore all loan guides and tools
Everything in one place, across secured loans, debt consolidation, and home improvementsUpdate log: July 2026
What changed in this update
Calculator accessibility improved: contrast ratios brought to WCAG 2.1 AA across all text elements, slider labels programmatically linked to inputs, screen reader support added for dynamic output updates and chart data, keyboard focus indicators added. Highlighted comparison cards now use a subtle background tint as well as a border for users with colour vision differences.
The streaming subscription comparison redesigned for clarity: now shows the number of streaming subscriptions your monthly interest cost is equivalent to, replacing a previous metric that could produce unintuitive figures. Comparison cards at slider boundary values now display a clear indicator rather than duplicating the current selection.
Article text updated to reflect that the tool’s term input uses years (not months), daily cost formula description aligned with the calculation method used, representative APR definition tightened to match FCA wording, and the distinction between APR (consumer credit) and APRC (mortgage products) clarified. Cross-links rebalanced to include personal loan tools alongside secured loan content, and a third related-tool card added for the loan term vs total cost explorer.
This tool is for illustrative purposes only and does not constitute financial advice. All calculations use the APR and term entered and assume a standard fixed-rate repayment loan with no fees beyond the interest cost. The daily cost figure is an average over the full term and does not reflect the actual daily accrual of interest on a reducing balance. Everyday comparison unit costs are illustrative only. Rate sensitivity and term trade-off panels use simplified assumptions and actual loan costs will vary by lender, product, and individual credit profile. The repayment equivalent projections are illustrative: the 7% return is not guaranteed and investment values can fall as well as rise. APR figures used should be taken from a personal loan illustration or offer, not a representative rate from an advertisement. Actual outcomes will depend on your individual circumstances.
