Equilibrium Explained: Where Supply and Demand Meet

Last updated: October 28, 2026

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If you have ever stared at an economics homework question that asks, in a long, roundabout way, for the name of one simple idea, you are not alone. Questions like this one are written to test whether you can recognise the concept hiding inside the wording, not whether you can memorise a whole chapter. Here on AllAboutFacts, we break that idea down in plain language, with a worked example you can reuse in class.

Table of Contents

Quick Answer

The point where supply and demand meet and prices are set is called equilibrium — more fully, market equilibrium. The price at that point is the equilibrium price, and the amount bought and sold there is the equilibrium quantity. It is the one price at which the quantity buyers want to buy exactly equals the quantity sellers want to sell, so there is neither a shortage nor a surplus.

What Is Equilibrium in Economics?

In economics, economic equilibrium describes a state of balance. In a market, the two sides of the scales are supply and demand.

Demand describes how much buyers are willing and able to buy at each price: when the price is lower, buyers want more, and when it is higher, they want less, so the demand curve slopes downward. Supply runs the other way: at a higher price sellers usually offer more, so the supply curve slopes upward.

Put those two curves on the same graph, with price on the vertical axis and quantity on the horizontal axis, and they cross at exactly one point. That crossing point is the equilibrium: the only price at which the plans of buyers and sellers agree. Be precise about the three terms, because exam questions often swap them: equilibrium is the point itself, the equilibrium price (also called the market-clearing price) is the price at that point, and the equilibrium quantity is the amount actually bought and sold there.

A Simple Supply and Demand Table

You do not need a graph to find equilibrium. A simple table, called a supply and demand schedule, works just as well: look down the rows until quantity demanded and quantity supplied are the same. Here is a classic textbook-style example for a petrol market.

  • $1.00: demand 800, supply 500 — demand higher.
  • $1.20: demand 700, supply 550 — demand higher.
  • $1.40: demand 600, supply 600 — a match. This is equilibrium.
  • $1.60: demand 550, supply 640 — supply higher.
  • $1.80: demand 500, supply 680 — supply higher still.

In this example, the equilibrium price is $1.40 per litre and the equilibrium quantity is 600 units. As price rises, the quantity demanded falls step by step while the quantity supplied rises, and the two meet in the middle. If a question gives you a table like this, scan for the row where the two quantities are equal.

What Happens Above and Below Equilibrium?

If the price is pushed away from equilibrium, market forces tend to push it back — and that is what most follow-up questions are really asking about.

Above equilibrium: a surplus. At $1.80 per litre, buyers want only 500 units but sellers offer 680. The extra 180 units sit unsold, so sellers cut prices and buyers buy more, and the price drifts down toward $1.40. Economists call this excess supply.

Below equilibrium: a shortage. At $1.20 per litre, buyers want 700 units but sellers offer only 550. Buyers competing for scarce stock bid the price up, sellers offer more, and the price drifts up toward $1.40. Economists call this excess demand.

That push-and-pull is the whole mechanism: surpluses push prices down, shortages push prices up, and equilibrium is where neither pressure exists. A market at equilibrium has no built-in reason to move — though, as the next section shows, resting points can move when conditions change.

When Equilibrium Moves: Shifts in Supply and Demand

Equilibrium is not frozen forever. When something other than the price itself changes, one of the curves shifts, and a new equilibrium forms. The four basic cases are worth learning as a set, because they appear in exams again and again.

  • Demand rises, supply unchanged: equilibrium price and quantity both rise.
  • Demand falls, supply unchanged: equilibrium price and quantity both fall.
  • Supply rises, demand unchanged: equilibrium price falls, quantity rises.
  • Supply falls, demand unchanged: equilibrium price rises, quantity falls.

What makes a curve shift? On the demand side: incomes, tastes, the price of related goods, or the number of buyers. On the supply side: production costs, technology, taxes, or the number of sellers. Remember the distinction between a movement along a curve, caused by a change in the good’s own price, and a shift of the whole curve, caused by something else changing.

Real-World Examples of Equilibrium

Textbook tables are tidy, but real markets are messier. At a farmers’ market at closing time, a stall with crates left drops its price to clear them, moving toward equilibrium. For a hugely popular concert, if the official ticket price is set too low, tickets sell out instantly and resell for far more — a shortage, in textbook terms.

None of this means real markets sit neatly at equilibrium all the time — prices can be sticky and governments can set price controls. Equilibrium is best understood as a benchmark showing where a competitive market tends to head.

How to Answer This Question in an Exam

If this exact wording appears on a test — “the point where supply and demand meet and prices are set is called” — the one-word answer is equilibrium. If the question asks for the price itself, answer equilibrium price. Adding one short sentence of explanation will usually earn full marks: “It is the price at which quantity demanded equals quantity supplied, so there is no surplus or shortage.”

A common trap is to answer with the name of a curve instead: the demand and supply curves are the two lines, not the point where they cross. Another trap is to describe the process without naming it. Lead with the term, then explain. The same habit helps with other classroom concepts on this site, such as Ethos, Pathos, and Logos Explained Simply for Students.

Frequently Asked Questions

What is the point where supply and demand meet called?
It is called equilibrium, or market equilibrium. The price at that point is the equilibrium price, and the quantity traded there is the equilibrium quantity.

What is the difference between a surplus and a shortage?
A surplus happens when price is above equilibrium and sellers offer more than buyers want. A shortage happens when price is below equilibrium and buyers want more than sellers offer.

Does equilibrium mean prices never change?
No. When demand or supply shifts, a new equilibrium forms at a different price and quantity.

Faizi is a content writer at AllAboutFacts (hotteamnames.com), covering vocabulary, language tips, and everyday explainers.

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