Equilibrium Price and Quantity Calculator

Supply and Demand Calculator: Enter Qd and Qs

Enter your demand function in the form Qd = a - bP and your supply function as Qs = c + dP. The calculator sets them equal, solves for the equilibrium price, then substitutes back to find the equilibrium quantity — and shows each line of the algebra rather than just the result.

The Equilibrium Price and Quantity Formula

At equilibrium, quantity demanded equals quantity supplied, so a - bP = c + dP. Solving for price gives P* = (a - c) / (b + d), and substituting P* into either function gives Q*. If your equations are written as P in terms of Q, the calculator rearranges them first.

Worked Example: Finding P* and Q*

Take Qd = 100 - 2P and Qs = 20 + 3P. Setting them equal gives 100 - 2P = 20 + 3P, so 80 = 5P and P* = 16. Substituting back: Q* = 100 - 2(16) = 68. Both functions return 68 at that price, which is the check worth doing on every problem.

The slope coefficients b and d are also what you need for the next question on most problem sets — feed P* and Q* into the price elasticity of demand calculator to get elasticity at the equilibrium point.

Surplus, Shortage, and Price Above or Below Equilibrium

Enter any price other than P* and the calculator reports the gap between quantity supplied and quantity demanded: a surplus when the price sits above equilibrium, a shortage when it sits below. This is the standard follow-up question on most problem sets.

Price floors and ceilings are the same calculation read backwards: a binding floor sits above P* and creates a surplus, a binding ceiling sits below P* and creates a shortage.

Find Price and Quantity with the Equilibrium Calculator

Identify the point where supply meets demand using our Free Market Equilibrium Calculator. This tool is a fundamental resource for economics students and market analysts looking to find the equilibrium price and quantity. By inputting the supply and demand functions, the calculator solves for the intersection point where there is no shortage or surplus in the market. It also helps you analyze how shifts in supply or demand affect the market clearing price. Gain a better understanding of price theory and market dynamics with this fast, automated economic solver.

For Economics Coursework and AP Economics Practice

Linear supply and demand problems from introductory microeconomics, AP Economics, and A-level economics are all in scope. Because the working is shown line by line, you can match it against the method your course expects.

For the rest of the syllabus, the AI economics solver handles word problems and graph questions that don't reduce to two equations. Macro topics have their own tools — the CPI inflation rate calculator for price indices and the terms of trade calculator for trade questions — while strategic interaction between firms belongs in the game theory payoff matrix solver. If your course pairs micro with corporate finance, the AI finance solver covers NPV, IRR, and valuation problems.

How It Works

Step 1: Access the Market Equilibrium Calculator
Open the economics calculator interface.

Step 2: Input the Demand Equation and the Supply Equation
Enter the formulas for quantity demanded (Q_d) and quantity supplied (Q_s).

Step 3: Click the Calculate Button
Press 'Find Equilibrium'.

Step 4: Review the Equilibrium Price and Quantity
The tool will display the price (P^*) and quantity (Q^*) where the two equations intersect.