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# Marginal Cost: Meaning, Formula, and Examples

August 6, 2024
Bill Kimball

Externalities are costs (or benefits) that are not borne by the parties to the economic transaction. A producer may, for example, pollute the environment, and others may bear those costs. A consumer may consume a good which produces benefits for society, such as education; because the individual does not receive all of the benefits, he may consume less than efficiency would suggest.

## Positive externalities of production

Of great importance in the theory of marginal cost is the distinction between the marginal private and social costs. It is the marginal private cost that is used by business decision makers in their profit maximization behavior. It incorporates all negative and positive externalities, of both production and consumption.

## What is the relationship between marginal cost and marginal revenue?

To calculate marginal cost, divide the difference in total cost by the difference in output between 2 systems. For example, if the difference in output is 1000 units a year, and the difference in total costs is \$4000, then the marginal cost is \$4 because 4000 divided by 1000 is 4. Meanwhile, change in quantity is simply the increase in levels of production by a number of units.

## What Is the Formula for Marginal Cost?

If you want to calculate the additional cost of producing more units, simply enter your numbers into our Excel-based calculator, and you’ll immediately get the answer. Marginal cost highlights the premise that one incremental unit will be much less expensive if it remains within the current relevant range. However, additional step costs or burdens to the existing relevant range will result in materially higher marginal costs that management must be aware of. Therefore, a company’s profits are maximized at the point at which its marginal costs are equivalent to its marginal revenues, i.e. the marginal profit is zero. By implementing marginal cost calculations in your financial analysis, you can improve the accuracy of your forecasts, make more informed decisions and potentially increase your profitability.

An increase or decrease in the volume of goods produced translates to costs of goods manufactured (COGM). On the other hand, the average cost is the total cost of manufacturing divided by the total units produced. The average cost may be different from marginal cost, as marginal cost is often not consistent from one unit to the next. Marginal cost is reflective of only one unit, while average cost often reflects all units produced. Marginal cost is often graphically depicted as a relationship between marginal revenue and average cost. The marginal cost slope will vary across company and product, but it is often a U-shaped curve that initially decreases as efficiency is realized only to later potentially exponentially increase.

Next, the change in total costs and change in quantity (i.e. production volume) must be tracked across a specified period. Marginal cost’s relationship with the production level is intriguing and has significant implications for businesses. As mentioned, the marginal cost might decrease with increased production, thanks to economies of scale. On the other hand, variable costs fluctuate directly with the level of production. As production increases, these costs rise; as production decreases, so do variable costs. Businesses may experience lower costs of producing more goods if they have what are known as economies of scale.

Marginal cost represents the incremental costs incurred when producing additional units of a good or service. It is calculated by taking the total change in the cost of producing more goods and dividing that by the change in the number of goods produced. During the manufacturing process, a company may become more or less efficient as additional units are produced.

ABC Wallets’ owners decide to produce more wallets every year, increasing their total annual production to 10,000 wallets. The warehouse has the capacity to store 100 extra-large riding lawn mowers. The margin cost to manufacture the 98th, 99th, or 100th riding lawn mower may not vary too widely. We put together a list of the best, most profitable small business ideas for entrepreneurs to pursue in 2024. The answers to these questions significantly influence a company’s financial health and competitive edge.

Economies of scale apply to the long run, a span of time in which all inputs can be varied by the firm so that there are no fixed inputs or fixed costs. Production may be subject to economies of scale (or diseconomies of scale). Conversely, there may be levels of production where marginal cost is higher than average cost, and the average cost is an increasing function of output. Since fixed costs do not vary with (depend on) changes in quantity, MC is ∆VC/∆Q. Thus if fixed cost were to double, the marginal cost MC would not be affected, and consequently, the profit-maximizing quantity and price would not change. This can be illustrated by graphing the short run total cost curve and the short-run variable cost curve.

On the right side of the page, the short-run marginal cost forms a U-shape, with quantity on the x-axis and cost per unit on the y-axis. The company has determined it will cost an additional \$400 to manufacture one additional bike. Although the average unit cost is \$500, the marginal cost for the 1,001st unit is \$400. The average and marginal costs may differ because some additional costs (i.e., fixed expenses) may not be incurred as additional units are manufactured. The purpose of analyzing marginal cost is to determine at what point an organization can achieve economies of scale to optimize production and overall operations.

1. However, management must be mindful that groups of production units may have materially varying levels of marginal cost.
2. Such production creates a social cost curve that is below the private cost curve.
3. For example, if a company needs to build an entirely new factory in order to produce more goods, the cost of building the factory is a marginal cost.
4. Understanding the relationship between changes in quantity and changes in costs results in informed decisions when setting production targets.
5. In many ways, a company may be at a disadvantage by disclosing its marginal cost.

Marginal cost, on the other hand, refers to the additional cost of producing another unit and informs cost pricing, but it isn’t the same thing. Finally, understanding a firm’s marginal cost can provide deep insights into its operational efficiency, profitability and growth prospects in investment banking and business valuation. To maximize efficiency, companies should strive to continue producing goods as long as the marginal cost is less than the marginal revenue. The total change in cost is \$5k, while the total change in production is 100 units. In the following year, the company produces 200 units at a total cost of \$25k.

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The marginal cost may first decline, as in the diagram, if the additional cost per unit is high, if the firm operates at too low a level of output, or it may start flat or rise immediately. At some point, the marginal cost rises as increases in the variable inputs such as labor put increasing pressure on the fixed assets such as the size of the building. In the long run, the firm would increase its fixed assets to correspond to the desired output; the short run is defined as the period in which those assets cannot be changed. Marginal cost is a production and economics calculation that tells you the cost of producing additional items. You must know several production variables, such as fixed costs and variable costs in order to find it. The total cost per hat would then drop to \$1.75 (\$1 fixed cost per unit + \$0.75 variable costs).

If the company makes 500 hats per month, then each hat incurs \$2 of fixed costs (\$1,000 total fixed costs ÷ 500 hats). In this simple example, the total cost per hat would be \$2.75 (\$2 fixed cost per unit + \$0.75 variable costs). Marginal cost is an important factor in economic theory because a company that is looking to maximize its profits will produce up to the point where marginal cost (MC) equals marginal revenue (MR). Beyond that point, the cost of producing an additional unit will exceed the revenue generated.

They are both decrease at first with the increase of output, then start to increase after reaching a certain scale. While the output when marginal cost reaches its minimum is smaller than the average total cost and average variable cost. When the average total cost and the average variable cost reach their lowest point, the marginal cost is equal to the average cost. Fixed costs do not change with an increase or decrease in production levels, so the same value can be spread out over more units of output with increased production. Costs of production (which include fixed costs as well as variable costs) increase with more production because producing more units means buying more raw materials and/or hiring more workers.

The amount of marginal cost varies according to the volume of the good being produced. The formula above can be used when more than one additional unit is being manufactured. However, management must be mindful that groups of production units may have materially varying levels of marginal cost. For example, the company above manufactured 24 pieces of heavy machinery for \$1,000,000.