Microeconomics

Marginal Revenue Calculator

Divide the change in total revenue by the change in quantity sold to find the marginal revenue per extra unit.

  • Free
  • No sign-up
  • Updated for 2026

Revenue & quantity change

$

Enter the changes to see marginal revenue.

Worked example

With these example inputs:

  • Change in revenue$5,000
  • Change in quantity200

Marginal revenue: $25

  • Change in revenue$5,000
  • Change in quantity200

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What marginal revenue is

Marginal revenue is the income from one more unit sold. It looks at the change, not the total. You enter the change in revenue. You also enter the change in quantity. The tool divides one by the other. The result is per extra unit. It answers what the next unit earns.

Why marginal revenue matters

It shows what the next sale really adds. A firm uses it to set output. If marginal revenue beats marginal cost, make more. If not, making more loses money. The figure guides smart pricing and volume. It turns a gut call into a number.

How to use this calculator

Enter two values. Put in the change in revenue. Then enter the change in quantity sold. The tool divides revenue by quantity. You read the marginal revenue per unit. Change either figure and it updates.

How it is calculated

The math is one division. Marginal revenue = change in revenue / change in quantity. You split the extra revenue across the extra units. The answer is the income per added unit. It sits in your currency. You can check the math in your head.

A worked example

Say revenue rose by five thousand. Quantity rose by two hundred units. Divide five thousand by two hundred. The marginal revenue is twenty five. That is what each extra unit brought in. Selling more added that much per unit.

Reading the result

The figure is income per extra unit. Set it next to your marginal cost. A gap above cost means profit on more. A gap below means a loss. The two together guide output. Make more only while revenue wins.

Marginal revenue and pricing

In a competitive market, price equals marginal revenue. With pricing power, the two can differ. Cutting price to sell more lowers it. Marginal revenue can even turn negative. Watch it as you change your price. A negative figure means the cut hurt.

Common mistakes to avoid

One slip is using total revenue, not the change. Another is mismatching the periods. People also mix up units of quantity. Each error skews the figure. Use matched changes for a true result. Match the same window for both inputs.

The limits of this tool

This calculator uses one pair of changes. It assumes a steady rate across them. It ignores costs and capacity limits. It also smooths over uneven demand. Use it as a quick guide. Pair it with real cost data.

Using marginal revenue to decide

Compare the figure to your marginal cost. Make more while revenue beats cost. Stop when they meet, the profit peak. Test a few changes to find the line. Let the numbers steer the volume. Stop short of selling at a loss.

A final tip

Recompute it as your sales shift. The figure moves with price and demand. Compare a few points to see the trend. A clear number keeps output on target. Recheck it whenever price moves.

Frequently asked questions

What is marginal revenue?

Marginal revenue is the extra revenue from selling one more unit. If revenue rises $5,000 when 200 more units sell, marginal revenue is $25 per unit.

Why does it matter?

Firms maximise profit where marginal revenue equals marginal cost. Tracking it shows whether selling more is still adding to the bottom line.