Using calculators with a lender illustration — amount, term, rate and fees

When a UK lender makes a personal-loan offer, the document in front of you — sometimes called a quote, illustration, or pre-contract credit information pack — already carries the fields LoanCalc Lab needs: how much you would borrow, over how many months, at what contractual rate, and which fees sit around the advance. The useful habit is not to invent round numbers from memory, but to copy those fields into the calculators and read the results as illustrative maths under stated assumptions. Our tools are not a second lender, not a regulated APR engine, and not a substitute for the figures on the agreement.

MoneyHelper notes that, by law, when you apply, lenders must tell you how much you will repay in total, how much you will pay every month, and the interest rates, fees or charges and the APR — information that must also appear in the pre-contract credit information form (MoneyHelper — Managing credit well). This page maps those fields to the personal loan / EMI calculator and the APR / true cost calculator. Every sample figure below is labelled EXAMPLE.

What “lender illustration” means here

Personal-loan paperwork is not a mortgage ESIS. On this site, “lender illustration” simply means the offer-side numbers a firm has given you for a regulated consumer-credit personal loan: face amount, term, contractual interest rate, monthly repayment, total amount payable, APR where shown, and any arrangement or product fee. Names vary by lender. The job is the same — find the four inputs our tools use (amount, term, rate, fees) and ignore marketing chrome until those four are locked.

Prefer the figures on your offer or pre-contract pack over a comparison-site representative example or an advert. Advertised representative APR answers a different question; see Representative APR — what the advertised rate does and does not mean.

The four fields to copy

• Amount (face principal). The loan amount the interest and EMI are calculated on — often labelled “amount of credit”, “loan amount” or “total amount of credit”. Copy the face figure, not “cash you might receive after a fee is deducted”, unless the document clearly states that the contractual principal is the net amount.
• Term. Duration in months (or years × 12). Align the calculator term with the offer term. Comparing a 36-month EXAMPLE run with a 60-month offer is not a like-for- like check.
• Rate. Use the contractual annual interest rate that sizes the repayment — not a representative advertising APR alone, and not LoanCalc Lab’s illustrative fee-adjusted “true cost” output. If the pack shows both a rate of interest and an APR, feed the interest rate into the EMI tool; treat APR as a cost-of-credit disclosure to read alongside fees.
• Fees. Arrangement, product, processing or setup fees that reduce cash received or sit on the advance. Enter them in the fee field of the true-cost tool. Late- payment or optional insurance charges belong in a separate reading of the agreement, not in a simple upfront-fee model.

Step 1 — amount, term and rate into the EMI calculator

Open the personal loan / EMI calculator, keep UK mode if you are working in pounds, and enter face amount, annual rate and term in months. Under LoanCalc Lab’s reducing-balance assumptions the tool returns a fixed monthly payment, total interest and total repayable. Compare those outputs with the monthly repayment and total amount payable on the lender document. Small differences can come from day-count, rounding, payment timing or fee treatment — large gaps mean a field was mis-copied or the lender’s model differs from ours.

EXAMPLE (Loan A style): suppose an offer shows face credit of £8,500 EXAMPLE, a contractual rate of 24.9% EXAMPLE, a term of 48 months EXAMPLE, and £0 EXAMPLE arrangement fee. Enter £8,500, 24.9 and 48 in the EMI calculator. The payment and totals are illustrative under our formula; they are not a quote and not the lender’s regulated schedule. For the interest-versus-principal story behind a fixed EMI, see How EMI works.

Step 2 — fees into the APR / true cost calculator

If the offer includes an upfront fee that is deducted from the advance (or otherwise reduces cash in hand while repayments amortise the face principal), copy amount, rate, term and fee into the APR / true cost calculator. That tool keeps EMI sized on the face principal and solves an illustrative effective yearly cost for the cash actually received. It is a teaching model — not a UK regulated APR and not the APR printed on the agreement.

EXAMPLE (Loan B style): face credit £12,000 EXAMPLE, rate 16.9% EXAMPLE, term 60 months EXAMPLE, arrangement fee £195 EXAMPLE deducted from the advance. Cash received in the simple model is £11,805 EXAMPLE while payments still service £12,000. The headline rate has not changed; the fee-aware cash-flow cost has. Read Fees & APR — headline rate vs true cost and Arrangement fees and APR for that split in more detail.

Always check how the fee is applied on the real pack: deducted, added to the balance, or billed separately. If the document finances the fee into a larger principal, enter the contractual principal the lender uses for interest — do not invent a hybrid the agreement does not describe.

Field map — offer wording to calculator inputs

• “Amount of credit” / “loan amount” → EMI and true-cost loan amount (face principal).
• “Duration” / “term” / “number of repayments” → term in months (convert years if needed).
• “Rate of interest” / “annual interest rate” → calculator annual rate. Prefer this over a lone advertising APR when sizing EMI.
• “Arrangement fee” / “product fee” / charges in the total charge for credit → true-cost upfront fee when the charge reduces cash received in the simple model.
• “Monthly repayment” / “instalment” → compare with EMI output; do not type the repayment into the rate field.
• “Total amount payable” / “APR” → sense-check against totals and the lender’s own APR disclosure; our illustrative effective rate is a separate number.

Common copy mistakes

• Pasting a representative APR from an advert as if it were your contractual rate.
• Using net cash after fee as the EMI principal when the agreement still charges interest on the higher face amount.
• Mixing term units (years into a months box, or the reverse).
• Ignoring a fee because the monthly payment “looks fine” — payment and fee-adjusted cost answer different questions.
• Treating calculator output as permission to borrow, or as more authoritative than the pre-contract pack and credit agreement.

MoneyHelper’s guidance on borrowing options stresses comparing the cost of credit carefully — including APR and how much you repay overall — rather than reacting to a single headline number (MoneyHelper — Options for borrowing money). The FCA’s Consumer Credit sourcebook sets how the total charge for credit and APR are determined for regulated agreements (FCA Handbook, CONC App 1). Copying fields into a calculator makes a comparison concrete under disclosed maths; it does not replace the lender’s disclosure or a statutory APR.

Practical checklist

• Work from your offer or pre-contract credit information, not from an advert alone.
• Copy face amount, term in months, contractual interest rate, then fees.
• Run amount / term / rate through the EMI calculator and compare monthly repayment and total repayable.
• If a fee reduces cash received, run the same deal through the APR / true cost calculator.
• Label any scratch figures EXAMPLE so they are never confused with a live quote.
• Prefer the lender’s APR, total charge for credit and agreement text whenever they diverge from illustrative outputs.

Disclaimer

This guide is illustrative educational material only. It is not personalised financial advice, not a credit offer, and not a recommendation to take or refuse any loan. LoanCalc Lab is not a lender. Calculator results use stated reducing-balance assumptions and may differ from a firm’s schedules, APR methodology or fee treatment. Pre-contract credit information and consumer-credit rules can change; always rely on the current lender disclosures and official guidance for your circumstances. All sample figures on this page are labelled EXAMPLE and are not quotes for any reader.