Is 5% interest always 5% per year?

No. The quoted period and convention must be stated. A 5% annual nominal rate, a 5% effective annual rate, and a 5% rate for another period can produce different cash flows.

What is the difference between an interest rate and a yield?

Interest rate often describes a contractual charge or payment relative to principal. Yield relates an investment's cash flows to its current price under a specified calculation. The two may be equal in a simple case but are not interchangeable.

Can a real interest rate be negative?

Yes. If inflation exceeds the nominal interest earned over the same period, the purchasing power of the ending amount can fall even though the amount of money rises.

Why did my loan rate not move with the central-bank rate?

It may be fixed, reset on a different schedule, or use another reference rate. Credit risk, maturity, funding costs, competition, fees, and contract terms can also cause it to move by a different amount or at a different time.

Interest Rates

Interest rates measure interest charged or earned over a stated period and affect borrowing, saving, and asset prices.

Published: August 24, 2026
Updated: August 24, 2026
Reviewed: August 24, 2026
Difficulty: Beginner
Editorial owner: Finance Repository Editorial Team
Reviewer: JH

Overview

Interest rates connect money today with money in the future. They affect borrowing costs, returns from lending or saving, and the present value of future cash flows.

There is no single interest rate for an economy. Rates differ across currencies, maturities, borrowers, products, and contract terms because they reflect different risks, costs, and expectations.

Interest is a payment across time

A lender gives up the use of money now in exchange for expected payments later. Interest can compensate the lender for waiting, expected inflation, the possibility of nonpayment, and other costs or risks. For a borrower, that same interest is part of the price of receiving funds before they could otherwise be accumulated.

If $1,000 earns simple interest at 5% for one year, it earns $50. If the $50 remains in the account and the balance then earns another 5%, the second year's interest is $52.50. The rate is unchanged, but compounding applies it to a larger balance.

The example assumes annual compounding, no fees, no taxes, and a constant rate. Real products may calculate interest daily, monthly, or by another convention, and payments or withdrawals can change the balance during the period.

Why quoted rates are not always directly comparable

A rate is meaningful only when its convention is known. Important distinctions include:

Periodic versus annual rate: a monthly rate and an annual rate cover different periods.
Nominal versus effective annual rate: a quoted nominal rate may not include the effect of compounding within the year, while an effective rate does.
Interest rate versus total borrowing cost: fees and required charges can make the total cost exceed the stated interest alone. Measures such as annual percentage rate follow rules that vary by product and jurisdiction.
Fixed versus variable rate: a fixed rate follows the contract's schedule; a variable rate can reset using a reference rate and a stated margin.
Simple versus compound calculation: simple interest uses the original principal, while compound interest applies to a balance that includes earlier interest.

Two accounts or loans with the same headline percentage can therefore produce different cash flows. A fair comparison uses the same balance, dates, payment pattern, compounding convention, and treatment of fees.

Nominal and real interest rates

A nominal interest rate measures growth in units of money. A real interest rate adjusts for inflation and describes the change in purchasing power.^[1]

For a quick estimate, the real rate is often approximated as the nominal rate minus inflation. If a deposit earns 5% while prices rise by 3%, the approximate real rate is 2%. The exact relationship is:

r_{r e a l} = \frac{1 + r_{n o m i n a l}}{1 + r_{i n f l a t i o n}} - 1

where

$r_{r e a l}$: the real interest rate
$r_{n o m i n a l}$: the nominal interest rate
$r_{i n f l a t i o n}$: the inflation rate over the same period

With 5% nominal interest and 3% inflation, the exact real rate is about 1.94%, not exactly 2%. The subtraction shortcut is usually close when both rates are modest. Both calculations require inflation and interest to cover the same period, and an individual person's spending pattern may differ from the price index used.

Why different borrowers pay different rates

Lenders consider more than a general market rate. A loan's rate can reflect:

the risk that the borrower will not make promised payments;
the length of time until repayment and uncertainty over that period;
whether collateral supports the loan;
how easily the loan or security can be sold;
the currency and expected inflation;
administrative, capital, funding, and competitive conditions;
options in the contract, such as the borrower's ability to repay early.

A higher rate may compensate for greater risk, but it does not remove that risk. Similarly, a low rate can reflect strong collateral or credit quality, a short maturity, policy conditions, or intense lender competition.

How central-bank rates spread through the economy

Central banks set or influence selected short-term policy rates in their own monetary systems. Those rates affect banks' funding choices and short-term market rates, which can in turn influence deposit rates, loan rates, bond yields, exchange rates, spending, and investment.

The transmission is neither immediate nor one-for-one. A mortgage rate, corporate bond yield, or savings rate also reflects maturity, credit risk, market expectations, competition, and product terms. Long-term rates can move before a policy decision when markets revise their expectations about future inflation, economic growth, or future short-term rates.

How rates affect asset values

An asset's value can be viewed as the present value of cash expected in the future. When the rate used to discount those cash flows rises, their present value generally falls, all else equal. This mechanism is most direct for fixed-rate bonds, whose contractual cash flows do not rise merely because market yields have increased.

Stocks, property, and businesses can also be affected, but their cash flows are not fixed. Higher rates may raise financing costs and discount rates, while inflation, growth, profits, rents, and expectations can move at the same time. It is therefore inaccurate to claim that a rate increase always makes every asset price fall.

Rate changes also redistribute cash flows. Borrowers with variable-rate debt may face higher payments, savers may receive more interest, and fixed-rate borrowers may see no immediate contractual change. The effect depends on the position, contract, and timing.

Frequently Asked Questions

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conceptBondsBonds are debt instruments whose prices and yields depend on payment terms, credit risk, and market interest rates.pathInvesting fundamentalsA guided introduction to investment risk, stocks, bonds, diversified portfolios, funds, fees, and a consistent investing process.topicEconomicsOrientation to prices, money, and purchasing power.

Sources

[1]
What are interest rates and what is the difference between nominal and real interest rates?
European Central Bank↩