Marginal revenue: definition, formula, and how to calculate it

Selling additional products or services usually sounds like a good thing, but that’s only true when every extra sale contributes to your overall bottom line. Marginal revenue can help you track those numbers by showing exactly how much additional income your business generates from selling one more unit. 

This makes it a powerful tool for making pricing decisions, evaluating discount strategies, and planning for scale. In this article, we’ll take a closer look at marginal revenue from both a theoretical and practical perspective so that you can use it to grow your profitability.

What is marginal revenue?

Marginal revenue (MR) is a measure of how much additional income a business earns from selling one more unit of a product or service. It’s calculated by dividing the change in total revenue by the change in quantity sold. The definition of marginal revenue matters because it tells businesses whether each new sale actually contributes to profit, not just to volume.

MR = Change in Total Revenue ÷ Change in Quantity Sold

What’s the difference between marginal revenue, marginal cost, and average revenue?

These three sound similar, but they’re actually set up to measure very different things.

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  Marginal revenue measures the additional revenue earned from selling one more unit of a product or service.

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  Marginal cost is the additional cost incurred from producing one more unit.

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  Average revenue is the total revenue divided by the number of units sold.

These metrics work closely together to inform pricing and production decisions. For profit to grow, marginal revenue must exceed marginal cost. Average revenue gives you a broad overview of performance, but marginal revenue gives you insight into whether your most recent sales are still profitable.

Brands trying to maximize profits will need all three metrics to ensure that earned revenue equals, at a minimum, the production costs and overhead required to sell and support a product or service.

How to calculate marginal revenue — step by step

To calculate marginal revenue, you need to ask this question: how much did revenue change when you sold one more unit? The marginal revenue formula makes the answer pretty straightforward, but it’s useful to walk through the logic.

For example, if you sell a pair of shoes for $50 and then sell one more unit at $50, your marginal revenue for that extra unit is $50.

While the concept is straightforward, the way marginal revenue is used varies depending on whether you’re looking at it in theoretical terms or trying to apply it to a real-world business situation.

Let’s use a B2B SaaS scenario as another example: a sales team closing an additional software seat. But keep in mind the same marginal revenue calculation applies whether you’re pricing a product, evaluating a discount, or modeling a new tier.

Scenario: Your team has closed 10 software seat licenses at $500 each. A prospect agrees to purchase an 11th seat, but only at $480. This is a negotiated discount to close the deal.

Step 1: Find your total revenue before the additional sale

Multiply the original price per unit by the original quantity sold.

10 seats × $500 = $5,000

Step 2: Find your total revenue after the additional sale

Only the new unit is discounted. The first 10 seats were already closed at $500.

$5,000 (original) + $480 (11th seat) = $5,480

Note: In a theoretical model, the lower price would apply to all 11 units ($480 × 11 = $5,280). In practice, MR reflects the revenue from that specific additional sale, which is $480.

Step 3: Calculate the change in total revenue

Subtract original total revenue from new total revenue.

$5,480 − $5,000 = $480

Step 4: Calculate the change in quantity

Subtract the original quantity from the new quantity.

11 − 10 = 1

Step 5: Divide to get marginal revenue

Change in total revenue ÷ change in quantity = marginal revenue.

$480 ÷ 1 = $480 marginal revenue

MR = Change in Total Revenue ÷ Change in Quantity Sold

MR = $480 ÷ 1 = $480

In this scenario, the marginal revenue from the 11th seat is $480, which is $20 less than the average revenue per seat across the other deals.

It’s up to you to decide whether that discount is worth accepting when you compare that $480 to the marginal cost of supporting an additional license.

Marginal revenue in theory vs. in practice

The way marginal revenue behaves depends on the type of market your business operates in. Before applying it practically, it helps to understand the theoretical baseline.

In microeconomics, MR is typically used to understand how revenue changes as output increases. This varies greatly depending on the type of marketplace that the business operates in.

• In a perfectly competitive market model, every seller offers the same product, and no single seller can influence price. All units are sold at the going market rate, and there’s no flexibility to charge more or less. In this model, marginal revenue is always equal to the market price and remains constant.

• In an imperfect marketplace model, sellers have some control over pricing. However, economic theory assumes that, to increase quantity sold, a business must lower the price. That price reduction applies to all units sold.

Imperfect marketplaces more closely resemble a real-world scenario, but they’re still well off the mark. Economic theory makes the assumption that you can only charge one price at a time for all units because products are identical, everyone has perfect information, and price discrimination isn’t allowed.

In this theoretical bubble, market saturation is reached when all buyers willing to pay that price have made their purchases. To capture a greater market share, businesses need to lower their prices to make their products more accessible and attractive to a wider range of customers.

Example: You’ve sold 10 units of shoes at $100 each. However, if you want to sell 11 units, you’ll need to lower the price to $98, bringing your revenue to $1,078—not $1,098—because all 11 units must be sold at the same price.

Why does MR function this way when used in theory?

Because theoretical MR is trying to answer the question: What if I sold one more unit of my product or service? The theory assumes that all sales generate the same revenue. In the example above, you’re either selling 10 units for $100 or 11 units for $98.

The result is a curve that shows each additional unit bringing in a little less overall revenue than the ones before it, which aligns with the standard marginal revenue formula:

MR = (Change in Total Revenue) / (Change in Quantity Sold)

This is the marginal revenue curve, which always slopes downward because additional units sold yield lower revenue per unit at a lower product price.

But remember, everything we’ve covered so far is purely theoretical. Marginal revenue, when applied to real-world scenarios, quickly breaks down as a standalone metric.

Marginal revenue in practice

In the real world, MR works differently than it does in economic models.

Businesses don’t typically lower the price of all units just to sell one more. Not all buyers pay the same rate to acquire a product. Pricing strategies are more flexible, segmented, and often customized based on volume, customer type, or market conditions.

All of this means that, in practice, marginal revenue is usually the revenue generated by the most recent sale rather than a blend of prices across all units.

Example: A business sells 10 pairs of shoes for $100, then offers a $10 discount on the 11th pair in order to close the deal.

In this real-world scenario, the marginal revenue is $90. The first ten units still earned $100 a piece. Changing the price of the last unit doesn’t retroactively alter its value.

Unlike theoretical models, most businesses can engage in price discrimination, meaning they charge different customers different prices based on their willingness to pay, order size, or relationship with the business. Additionally, earned revenue may vary widely across sales channels, further complicating this issue.

However, in a realistic scenario, marginal revenue also becomes a more practical, tactical metric. When calculated and applied correctly, MR can tell you any of the following:

• How much revenue is each additional sale bringing in?

• Are we maintaining profitable unit economics as volume increases?

• Do our sales justify our production, shipping, or fulfillment costs?

• Is a discount necessary, or should we stop offering the product at all?

Marginal revenue becomes especially useful when pricing isn’t fixed or when product delivery has variable costs. This is common in industries like SaaS, healthcare, and manufacturing, which is why many of these industries rely on CPQ software to keep all variables straight. This information can help teams evaluate whether sales are worth pursuing and whether growth is actually contributing to overall profitability (not just volume).

Rather than being tied to theoretical constraints, MR in practice is used on a case-by-case basis to help businesses assess performance and make informed decisions based on sales and campaign data initiatives, as well as other key data points.

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Why marginal revenue matters for profit maximization

At its core, calculating marginal revenue helps businesses know whether selling additional units of a product will actually generate more money.

While it might seem like revenue increases with additional sales, that isn’t always true due to the cost of production — called the marginal cost (MC) — when making additional products. How these two metrics align with one another is something like this:

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  Marginal profit is calculated by subtracting marginal cost from marginal revenue.

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  If marginal revenue exceeds marginal cost, you’re making more revenue than the unit costs to produce, so you can keep selling.

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  If marginal cost exceeds marginal revenue, you’re spending more to sell than you’re making back, so you’re selling at a loss.

Knowing MR allows teams to compare production costs to overall profits and make a decision about whether it makes sense to continue selling a product or service. In this way, businesses can avoid chasing volume over value.

Example: You’ve sold 10 pairs of shoes for $100 apiece, but you actually have 500 pairs of shoes in your warehouse.

You need to sell more shoes, but you’ll need to lower the price to do it because buyers aren’t interested in paying $100 for your shoes.

Lowering the price is likely to increase demand, but it also lowers your MR. Depending on how you do it (sale, price reduction, rebate, etc.), calculating your MR might not be straightforward.

At the same time, it costs $55 to make each pair of shoes. This is your marginal cost, so your average price needs to exceed production costs in order to make a profit. Now, you’ll need to decide whether to lower your price and accept slimmer margins, pull the product from shelves, or wait and see if buyer demand rises on its own over time.

You’ve probably noticed that MR is only one part of the equation. To calculate something like marginal profit, you’ll still need to know your production level and the overall cost it takes to produce an additional item. Once you have the data, MR becomes a powerful filter for decision-making.

Bottom line: If the selling price generates MR that exceeds production costs, every sale contributes to profit. If not, you’re losing money and wasting resources.

The relationship is straightforward: when MR exceeds MC, keep selling. When MC exceeds MR, stop. Every additional unit is costing you more than it brings in. Profit peaks at the point where the two are equal, which is why MR = MC is the standard benchmark for profit-maximizing output.

Common mistakes when interpreting marginal revenue

While MR is a simple concept on the surface, it’s easy to misinterpret when applied to real-world business scenarios.

Here are some of the most common mistakes companies make when working with marginal revenue.

Confusing MR with total revenue or average revenue

One of the most common mistakes is assuming that marginal revenue is just another way of saying “total” or “average” revenue. However, this isn’t true.

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  Total revenue is the full amount you’ve earned from all sales combined.

• 
  Average revenue is the total revenue divided by the number of units sold.

• 
  Marginal revenue is the revenue earned from selling one additional unit of a product or service.

Although these metrics are related, they aren’t interchangeable, and mistaking one for another can lead to flawed forecasting, mispriced products, or incorrect assumptions about profits.

Of the three, MR gives the most current insight into short-term profitability. Where both total and average revenue give better long-term projections, MR can help you project short-term profitability based on the numbers from your most recently sold units.

Ignoring how price changes affect MR

If you change your price to drive sales through a discount, promotion, or negotiation, you’re affecting MR whether you realize it or not.

Many businesses lower prices to increase volume without calculating whether additional units sold are actually contributing to profit. If MR drops below your total cost per unit — including production, shipping/delivery, and warehousing — you’re losing money on every extra sale, even if total revenue is going up.

This is especially easy to overlook in fast-moving and competitive sales environments, where companies rush to counter the price elasticity of demand by lowering prices to keep buyers engaged.

Forgetting fixed and variable cost context

Marginal revenue only tells one side of the story. If you’re not also considering the marginal costs, you won’t have a full picture of your production expenses. Variable costs like materials, labor, packaging, or shipping are also critical for these calculations because they influence the cost of production.

One common mistake is to assume that you’re automatically more profitable because you’re earning more money. But fixed costs like rent or software subscriptions don’t scale over time the way that variable costs will.

Example: Assume you charge $1,000 each year for a service subscription.

Through metrics and tracking, you can see that the average cost required to onboard and support a customer year over year is $500. This is a combination of required staff support, ongoing product development and maintenance, etc.

However, next year, both your facilities and labor costs increase. Now, it costs $575 to support a customer. Even though you’re still making money (MR is flat), the “floor” for profitability has risen in ways that won’t appear in financial statements or earnings reports.

If your variable costs increase over time but the cost of your final products remain the same, profits can disappear even though revenue continues to rise on paper.

Assuming MR is always positive

In reality, marginal revenue can fall to zero or even go negative.

This usually happens in saturated markets or when steep discounts are used to chase sales. If you’re lowering your price aggressively in order to move units, it’s possible that revenue from those extra sales is lower than the revenue you would have earned by selling fewer units at a higher price.

In extreme cases, you might move more product but make less money overall. That’s a dangerous outcome if you’re not actively tracking the impact of your pricing strategy by revenue generated per unit.

Treating theoretical MR as a practical metric

Economic models are helpful for understanding how marginal revenue works in principle, but applying theoretical MR to real business decisions can be a big mistake for your team.

In theory, MR assumes that a single price applies to all units, that buyers have the perfect information, and that price discrimination doesn’t exist. None of these things are true in practice.

Real businesses use tiered pricing, negotiate deals, offer discounts to certain segments, and sell across multiple channels. All of these things can create MR figures that are nothing like the curve we’re talking about.

This mistake happens when teams use theoretical MR benchmarks to set pricing floors, forecast revenue, or evaluate whether a sale is worth pursuing. But they don’t account for the conditions those benchmarks assume. A declining MR curve in a model doesn’t mean your next deal will be unprofitable, it just means that the model says so under assumptions that don’t always apply.

So the bottom line: use theoretical MR to understand direction and behavior, and use real transaction data to make decisions.

Marginal revenue strategies to maximize profit

As a metric, marginal revenue isn’t that useful by itself. It begins to have a strategic impact when used alongside other data points, pricing insights, and business intelligence.

When used in that context, marginal revenue can play a role in fine-tuning your pricing, aligning production goals with sales goals, and helping to grow your profit without sacrificing overall value.

Let’s take a closer look at how you can use MR values to generate additional profit

Pricing elasticity analysis

Before committing to a full pricing shift, test how demand responds to small price changes. If lowering price by 5% increases unit sales by more than 5%, MR stays positive and the move is worth making. If volume doesn’t compensate for the price reduction, you’re selling into margin destruction, not growth.

Dynamic or “surge” pricing allows competitive firms to adjust prices in real time when responding to market conditions, maximizing revenue when demand is high while remaining competitive when demand softens. Especially when pricing is automated, tracking MR over time and analyzing those outputs can help businesses understand when and how current pricing solutions balance cost and demand.

Similarly, bundling or volume-based pricing can increase transaction size without significantly increasing cost. When you track MR across these approaches, you can assess the return on each deal and ensure pricing decisions are grounded in actual margin impact and not intuition.

What this looks like in practice: A SaaS team considering a plan price reduction can run a limited test across a customer segment before rolling it out broadly. They can use the MR impact to determine whether the change improves or undermines profitability at scale.

Discount evaluation

A discount that closes a deal isn’t necessarily a good discount. You can use MR to assess whether the discounted unit still generates more revenue than it costs to produce and deliver. If the MR of that final unit exceeds its marginal cost, the deal is worth taking. If it doesn’t, you’re closing business at a loss.

Upselling and cross-selling are helpful as they increase the value of a sale while keeping costs relatively low. This keeps MR healthy without needing to reduce price in order to drive volume.

What this looks like in practice: A sales rep can offer a 15% discount to close a deal at quarter-end, but they need to know whether that price still clears the cost threshold, and not just whether it hits quota. The right quoting software has those guardrails in place, so your reps can offer competitive pricing without eroding margin on every deal they close.

Product mix decisions

Not all of the products or service tiers you’re selling are necessarily pulling equal weight. MR analysis can show you which product lines are still contributing to positive revenue. They’ll also show you which have declining returns, which can tell you to deprioritize or discontinue them.

What this looks like in practice: A company that offers three software tiers could use MR data to discover that its entry-level plan generates minimal marginal revenue per new customer compared to the support costs it triggers. This will help inform their decision to either reposition or remove it from the pricing page.

Scaling decisions and customer segmentation

Before adding headcount, inventory, or production capacity, MR can tell you whether the additional output will create more revenue than it costs to produce. Scaling into declining MR, where each additional unit brings in less than it costs, is a common way businesses grow revenue while actually shrinking profit.

Customer segmentation makes this more precise. Not all customers respond the same way when it comes to pricing. Marginal revenue can help identify how different market segments respond to changes in price.

Some customer groups are highly price sensitive and will only convert when the price drops. Others are more focused on quality, convenience, or brand loyalty and will pay a premium without significant impact on demand. Marginal revenue analysis helps businesses identify which segments justify discounts or incentives and which don’t, so promotional spend goes where it actually moves margin, not just volume.

For example, in SaaS industries, offering tiered plans or usage-based pricing allows teams to extract more value from high-usage customers without overextending resources.

What this looks like in practice: A manufacturer who’s considering a third production shift can use MR analysis to confirm that the additional units it would produce can be sold at a price that still exceeds marginal cost. The manufacturer gets this information before committing to the labor and overhead required to make that shift.

Put your revenue strategy into motion with PandaDoc

Marginal revenue might seem like a simultaneously pointless and insightful metric, especially if you’re only using it in a theoretical sense. When paired with production costs, pricing strategy, or real customer behavior, or additional metrics, it becomes a powerful figure to assist with profitability.

Calculated and considered correctly, MR can help you spot where growth is truly beneficial and where selling more may actually hurt your bottom line. By applying this sort of thinking across an entire operation, businesses can fine tune strategies and make smarter decisions about when to push forward, when to hold back, and where to focus to achieve greater returns.

PandaDoc helps growing teams put these strategies into action with powerful CPQ solutions. Our platform makes it easy to build complex pricing models, customize quotes for different customer segments, and adjust pricing dynamically without slowing down your sales cycle. By streamlining your quoting process and giving your teams more control over how deals are structured, PandaDoc CPQ helps to ensure that MR stays high, costs stay predictable, and profitability stays on track as you scale

See how PandaDoc CPQ works by booking a demo with one of our product specialists.