What it means
An APR answers the question of what a loan costs over a year in percentage terms. Lenders quote it because it is required by consumer credit rules in most countries, and because a single figure is far easier to compare than a mix of rates, arrangement fees and charges.
The subtlety is that APR is normally a simple annual rate, calculated as the periodic rate multiplied by the number of periods in the year. If a card charges 1.825% a month, the quoted APR is 21.9%, even though monthly compounding makes the true annual cost higher.
That is why the effective annual rate, sometimes called EAR or APY, exists alongside it. The effective rate compounds the periodic rate over the full year and always comes out equal to or higher than the APR for the same loan.
Which fees are included varies by product and jurisdiction. Mortgage APRs often fold in arrangement and valuation fees, which is why the APR on a mortgage is typically higher than the headline interest rate quoted in advertising.
For business borrowers the practical warning is about short-term facilities. A merchant cash advance or invoice finance deal quoted as a flat 4% fee over sixty days looks cheap, but expressed as an APR it can exceed 30%, which is the only fair basis for comparing it with a bank overdraft.
In practice
Real-world examples.
Example
A restaurant owner compares a bank loan at 9.5% APR with equipment finance quoted as "just 5% of the value". Converting the finance deal to an APR shows it costs over 18% a year once the twelve-month term is taken into account.
Example
A homebuyer sees two mortgages with the same 5.2% interest rate but APRs of 5.35% and 5.75%. The difference is arrangement fees, and over the first few years the lower APR product is clearly cheaper.
Example
A finance manager reviewing supplier terms works out that skipping a 2% discount for paying within ten days, on invoices due in thirty days, is equivalent to borrowing at an APR above 36%. She switches to paying early.
Think of it
“APR is the real yearly borrowing cost-complete cost of the loan.
Formula
Calculation
APR = Periodic Interest Rate x Number of Periods per Year. Effective Annual Rate = (1 + Periodic Rate) raised to the power of the number of periods, minus 1.
A business credit card charges interest at 1.825% per month. The APR is 1.825% x 12 = 21.9%, which is the figure that must appear in the terms.
On a balance of $4,000 carried for one month, the interest charged is $4,000 x 0.01825 = $73.00. If the balance were carried unpaid for a full year with interest compounding monthly, the effective annual rate would be 1.01825 raised to the power of 12, minus 1, which equals 24.24%.
So a card advertised at 21.9% APR actually costs about 24.2% a year on a persistently carried balance. On $4,000 that is roughly $969 of interest over the year rather than the $876 the simple APR suggests.Case study
Seen in the real world.
Rothwell Garden Centres is an invented company used for this illustrative story. Facing a cash squeeze before the spring season, its owner accepted a $200,000 advance from a funding provider that charged a fixed fee of $16,000, repayable in daily instalments over roughly six months.
The 8% fee sounded modest set against the alternative bank facility quoted at 11% APR. What the owner had not done was annualise it: an 8% charge over half a year is close to 16% a year before allowing for the fact that daily repayments meant the average balance outstanding was far below $200,000, which pushed the true APR above 30%.
After the season the finance team rebuilt the comparison on an APR basis and moved to a conventional overdraft. In this fictional example the switch saved roughly $22,000 a year, purely from comparing costs on a consistent measure rather than on headline fee percentages.
Watch out
Common mistakes.
- Treating APR and the effective annual rate as the same thing, when compounding within the year makes the effective rate higher.
- Comparing a short-term fee, such as 4% over sixty days, with an annual rate without converting it to an annual basis first.
- Assuming every fee is captured in the APR. Late payment charges, early repayment penalties and some insurance costs are usually excluded.
Questions
People also ask.
Why is a mortgage APR higher than the advertised interest rate?
Because the APR spreads arrangement and other required fees across the life of the loan, while the headline rate covers interest only.
Does a 0% APR promotion really cost nothing?
Only if the balance is cleared before the promotional period ends, since deferred interest or a sharp rate rise afterwards is common.
Which is better for comparing investments, APR or effective annual rate?
The effective annual rate, because it reflects compounding and therefore what you actually earn or pay over the year.
From the founder's library
Take it further with the book.
Build your financial confidence beyond this definition. Shihan's full-length guide, Accounting Fundamentals, takes the same plain-English approach and turns it into a complete, practical playbook for non-finance managers, business owners and students - with chapter-end quiz answers and presentation slides included.
25% off with code MMHQ25, applied at checkout. Priced in USD - checkout may show the equivalent in your local currency.
View the book and save 25%