Initial markup formula with a retail worked example

Every price a store puts on a product starts with one decision: how far above cost to set the first ticket. Retail buyers call that figure IMU. This guide explains the calculation with a fictional worked example, separates IMU from the percentages it is confused with, and shows how a small multi-store retailer plans it by category.

What is IMU in retail

IMU is the difference between the original retail price of an item and its cost, expressed as a percentage of that original retail price. It is set before the goods reach the shelf, which is why it is called initial. It describes the planned markup, not what the store earns once reductions are taken.

Retail buyers quote IMU on retail, not on cost, so a $25 ticket on a $15 item is a 40% IMU, not 66.67%. Cost usually means landed cost: the invoice price plus inbound freight, less any trade discount.

IMU formula

IMU % = (original retail price − cost) ÷ original retail price × 100

Rearranged, the same relationship gives the price for a planned IMU: retail = cost ÷ (1 − IMU). A $15 item planned at 40% is priced at $15 ÷ 0.60 = $25.

How to calculate IMU

Take a fictional item that costs $15 landed and is ticketed at $25.

1. Subtract cost from the original retail price: $25 − $15 = $10 of markup per unit.
2. Divide by the original retail price: $10 ÷ $25 = 0.40.
3. Multiply by 100: 40% IMU.

The free MMU calculator runs this from the unit cost and original retail price you type, then continues to the maintained figure described below. It works without an account and saves nothing.

Markup on cost vs markup on retail

The same $10 on the same item gives two percentages depending on the denominator. On cost, $10 ÷ $15 = 66.67%. On retail, $10 ÷ $25 = 40%. A wholesaler's "keystone" rule (double the cost) speaks in markup on cost. A buying plan, an open-to-buy and most retail reports speak in markup on retail, which is the IMU convention.

"Mark it up 40%" means $21 read on cost and $25 read on retail, so write the basis next to every percentage. Investopedia's markup entry sets out the cost-based form, and the free price-and-cost calculator shows both percentages for any pair of numbers.

IMU vs margin

Gross margin and IMU share a denominator, retail, so they are often treated as one figure. IMU is the planned markup on the original ticket before anything happens to it. Gross margin is what the business kept after the goods sold at whatever price they achieved. On a unit sold at full price the two are equal; on a unit that was marked down, margin is lower than IMU by the markdown.

The gap is markdowns, shrink and discounts, and it should be planned, not discovered. Investopedia's comparison of margin and markup covers the arithmetic.

Maintained markup after markdowns and shrink

MMU is the markup the store achieved once the goods sold: actual selling price less cost, divided by actual selling price. Suppose the $25 item sold for an average of $22 across the season after one round of reductions. MMU = ($22 − $15) ÷ $22 = 31.82%. The reductions came to $3 on a $25 ticket, or 12% of the original retail price.

The distance between the first two rows is the figure to watch across seasons. A widening gap means markdowns or shrink are growing faster than the opening price allows for. The retail markdown strategy guide covers the markdown half of that gap.

Planning IMU backwards from expenses

The planning formula works from what the business needs rather than from what a vendor charges. Expressed as percentages of planned net sales:

Planned IMU % = (expenses + profit + reductions) ÷ (net sales + reductions)

Reductions are markdowns, shrink and employee discounts added together. The denominator is larger than 100% of sales because the goods were ticketed above what they eventually sold for. A fictional plan illustrates it:

In words, the store needs 38 cents of every sales dollar for expenses and profit, expects to give up another 12 cents of ticket value to reductions, and so has to open at about 44.6%. Shopify's retail math guide lists this formula with the other planning ratios.

Cumulative markup across a season

CMU is the markup on everything a department handled during a period: opening inventory plus purchases, each at retail and at cost. In a fictional department, opening stock of $20,000 retail cost $11,000, and purchases of $30,000 retail cost $17,000. Total retail is $50,000 against $28,000 of cost, so CMU = $22,000 ÷ $50,000 = 44%. Buyers use it to check whether the season's purchases are on track for the planned IMU; the open-to-buy guide shows where that check sits in the buying calendar.

Setting IMU by category

One markup for the whole store is rarely right. Categories that take heavy seasonal markdowns, such as fashion and gifts, need a higher IMU to leave room for them. Staples that sell at full price all year and turn quickly can carry a lower one and still return more on the money invested; the free GMROI calculator shows that trade-off from figures you enter. The stock-to-sales ratio guide covers the stock side of the same plan.

headoffis records manual sales at the unit selling price after discounts and before tax, and its Analytics page compares sales value and units sold across periods and locations. It does not hold product costs or calculate profit, so IMU and MMU planning stays in your buying spreadsheet or the free calculators.

IMU meaning in retail and the acronyms

IMU stands for initial mark-up: the first markup placed on goods, before any reduction. Outside retail the same three letters carry unrelated meanings in online slang and in engineering, so results for the acronym alone can be noisy. This page uses the retail term only.

MMU meaning in retail

MMU stands for maintained mark-up. It is the markup still in place after markdowns, shrink and discounts have reduced the original ticket, measured on the actual selling price.

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