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Effective Interest Rate Calculator: Amortised Cost under FRS 102

Find the effective interest rate on a loan, bond or note after fees and transaction costs, and get the amortised cost schedule required by FRS 102 Section 11.

Updated Rates checked 16 October 2026 Free · no sign-up

Work out the effective interest rate and amortised cost

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Repayment profile

Follows FRS 102 paragraphs 11.13 and 11.15 to 11.20 for a fixed-rate basic financial instrument held at amortised cost, with fees and transaction costs included in the initial carrying amount. The defaults reproduce the FRC’s worked example. It does not cover below-market or interest-free loans (which are measured at present value under paragraph 11.13), variable rates, prepayment options, impairment, modifications or IFRS 9 expected credit losses.

What the effective interest rate is

Under FRS 102 Section 11, basic debt instruments such as bank loans, bonds, loan notes and intercompany loans are usually measured at amortised cost using the effective interest method. Paragraph 11.16 defines the effective interest rate (EIR) as the rate that exactly discounts the estimated future cash payments or receipts over the expected life of the instrument to its carrying amount at initial recognition. IFRS 9 uses the same idea for entities reporting under IFRS.

The EIR differs from the coupon rate whenever the amount first recognised differs from the amount the coupon is charged on. That happens when there are:

  • Fees and transaction costs. Arrangement fees, legal costs and broker fees directly attributable to the loan;
  • Discounts and premiums. A bond bought for less than its face value, or one redeemed at a premium;
  • Stepped or unusual interest. Payment holidays, rising coupons or a final balloon payment.

Initial measurement

Paragraph 11.13 measures a basic financial instrument at its transaction price adjusted for transaction costs. For a lender, a loan is recognised at the cash advanced plus transaction costs. For a borrower, a bank loan is recognised at the cash received less separately incurred transaction costs. Paragraph 11.18 then requires fees, transaction costs, premiums and discounts to be spread over the expected life of the instrument through the EIR, rather than expensed up front.

Building the amortised cost table

Paragraph 11.15 sets amortised cost as the amount at initial recognition, less principal repaid, plus or minus the cumulative amortisation of any difference between that amount and the maturity amount. In practice each period works like this:

ColumnHow it is calculated
Opening amortised costInitial carrying amount, then last period's closing balance
Interest at the EIROpening amortised cost × EIR for the period (paragraph 11.16(b))
Cash paid or receivedContractual coupon and any capital repayment
Closing amortised costOpening + interest − cash

By maturity the closing balance equals the final repayment, so the fees and any discount have been released through interest over the life of the instrument.

Worked example from FRS 102

The FRC's own example follows paragraph 11.20. On 1 January 20X0 an entity buys a bond for CU900, paying transaction costs of CU50. It receives interest of CU40 a year in arrears for five years, and the bond is redeemed for CU1,100 on 31 December 20X4. The initial carrying amount is CU950.

YearOpeningInterest at 6.9583%Cash receivedClosing
20X0950.0066.11(40.00)976.11
20X1976.1167.92(40.00)1,004.03
20X21,004.0369.86(40.00)1,033.89
20X31,033.8971.94(40.00)1,065.83
20X41,065.8374.16(40.00)1,100.00

The calculator's default inputs reproduce this example. Enter the principal as 1,000 with a 4% coupon to give CU40 a year, the cash paid as 900, costs of 50 and a redemption amount of 1,100. It returns an EIR of 6.9584% (6.95845% to five decimal places). The FRC prints the rate as 6.9583% and shows final-year interest of 74.16, where the calculator gives 74.17; these are rounding differences in the published table, and every other figure matches to the penny. Total interest income over the five years is CU350: CU200 of coupons plus the CU150 difference between the CU950 carrying amount and the CU1,100 redemption.

Annuity loans and payment frequency

For a repayment loan with level instalments, choose the annuity profile. The calculator works out the instalment from the coupon rate and term, then solves the EIR from the instalments and the initial carrying amount. With half-yearly, quarterly or monthly payments the rate is solved per period. The table then adds up each year's periods, and the headline shows the annual equivalent rate, (1 + periodic rate) raised to the number of periods a year, minus 1. That is a compounding convention, not a consumer credit APR.

What this calculator does not cover

  • Below-market and interest-free loans. Director, employee and intercompany loans at a non-market rate are financing transactions under paragraph 11.13, measured at the present value of the payments at a market rate. Paragraph 11.13A gives some small entities an exemption;
  • Variable rates. Paragraph 11.19 re-estimates cash flows as market rates change;
  • Changes in estimates. Paragraph 11.20 requires a catch-up adjustment at the original EIR when expected cash flows change, for example on early repayment;
  • Impairment and expected credit losses. Neither impairment under FRS 102 nor IFRS 9 loss allowances are modelled;
  • Irregular cash flows. Payment holidays, stepped coupons and part repayments need a bespoke schedule.

Getting the accounting right

Expensing loan arrangement fees on day one, rather than spreading them through the EIR, does not follow paragraph 11.18. Our FRS 102 accounts team sets up amortised cost schedules for bank debt, loan notes and intercompany balances, and our IFRS accounts service covers the IFRS 9 equivalent. Companies funding research can also use our R&D tax credit calculator.

Common Questions

Frequently Asked Questions

What is the effective interest rate under FRS 102?
FRS 102 paragraph 11.16 defines it as the rate that exactly discounts the estimated future cash payments or receipts over the expected life of the instrument to its carrying amount at initial recognition. Because that carrying amount includes fees and transaction costs, the EIR differs from the coupon rate whenever there are fees, a discount or a premium.
How do arrangement fees affect the effective interest rate?
For a borrower, fees are deducted from the amount first recognised, so a £100,000 five-year loan at 6% with £2,000 of fees starts at £98,000 and the EIR rises above 6%. Total interest expense over the life is £32,000: £30,000 of coupons plus the £2,000 of fees spread over five years.
How is the amortised cost table built?
Each period starts with the opening amortised cost, adds interest at the EIR on that opening balance, and deducts the cash paid or received. The closing balance becomes the next opening balance, and by maturity it equals the final repayment, as in the FRC's own five-year bond example.
What EIR does the FRC example give?
In the FRS 102 example a bond is bought for CU900 plus CU50 of costs, pays CU40 a year for five years and is redeemed at CU1,100. The FRC quotes an EIR of 6.9583%, with interest income of CU66.11 in year one rising to CU74.16 in year five. This calculator reproduces the table and gives 6.9584% and CU74.17 for the last year, differences that come from rounding.
Is the effective interest rate the same as APR?
No. The EIR is an accounting measure used to spread interest and fees. The APR on consumer credit is set by consumer credit rules and can include different charges. This calculator also shows an annual equivalent rate, which simply compounds the periodic EIR over a year.
Does this work for an interest-free director's or intercompany loan?
Not directly. A loan at below a market rate is a financing transaction under paragraph 11.13 and is first measured at the present value of the payments discounted at a market rate, unless a small entity exemption applies. That needs a market rate assumption this calculator does not ask for.
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