This page explains the replenishment quantity: the exact number of pieces to order once a style's reorder point has been reached, calculated to bring stock up to a target level without overshooting it. It is for a domestic Make to Stock buyer, such as Cedar & Co., who already knows a style has reached its reorder point.
At work, reaching a reorder point answers only one question, that an order should be placed now; it does not answer how many pieces that order should be. Ordering too few risks a second stockout before the next replenishment cycle completes. Ordering too many creates excess stock: pieces that sit unsold, tying up money and eventually needing a markdown to clear. This lesson gives you the method for calculating a replenishment quantity that covers real expected demand without overshooting into excess.
You need: lesson 2.2's reorder point method is useful background but not required.
By the end of this lesson you can:
Not covered here: calculating the reorder point that triggers the order (lesson 2.2); adjusting the quantity once real sales run faster or slower than planned (lesson 2.4).
| Term | Meaning |
|---|---|
| Replenishment cycle | One repeating round of Make to Stock production, run against a forecast rather than a single confirmed order. |
| Weekly sales rate | The average number of pieces of a style sold in one week, found by dividing total pieces sold by the number of weeks elapsed. |
| Opening stock | The stock a retailer holds at the very start of a given week, before that week's own intake or sales are counted. |
| Intake | New stock arriving into a retailer's own stockroom or distribution centre in a given week, from a confirmed order. |
| Excess stock | Stock ordered beyond real expected demand, left unsold and tying up money until it is cleared, often at a markdown. |
| Reorder point | The quantity of stock remaining at which a Make to Stock buyer places its next production order against the standing forecast. |
The replenishment quantity is calculated, not chosen. First, a target stock level is set: enough stock to cover expected sales across the full replenishment cycle ahead, at the style's own weekly sales rate. Second, the quantity already on hand, the opening stock at the point of ordering, is subtracted from that target. The result is the exact replenishment quantity: enough to reach the target, no more. Skipping the subtraction step, and ordering the full target level regardless of what is already on hand, is the single most common way a buyer ends up holding excess stock it never actually needed.
| What can differ | The shapes you will meet | Why it matters |
|---|---|---|
| Domestic, Make to Stock, short cycle | Cedar & Co. runs a 4-week replenishment cycle for its basic T-shirt style, reordering continuously against its own factory relationship. | A short, frequent cycle keeps the target stock level, and so the replenishment quantity, relatively small each time. |
| Export, Make to Order, longer cycle | A Northline Apparel style reordered through Delta Garments covers a longer cycle, since production restarts fully for each run. | A longer cycle raises the target stock level, since it must cover more weeks of expected sales before the next order arrives. |
| Stock already on hand is unusually low | A style whose opening stock has fallen further than usual because of a short local sales spike. | A lower opening stock raises the replenishment quantity needed to reach the same target level. |
| Stock already on hand is unusually high | A style with returned stock recently added back to opening stock before the calculation is run. | Failing to subtract this stock correctly is exactly how an order becomes larger than needed, creating excess stock. |
Cedar & Co.'s T-shirt style, similar in construction to Order A, has just reached its reorder point. Cedar & Co. runs a 4-week replenishment cycle and now calculates exactly how many pieces to order, rather than simply reordering a familiar round number from a previous season.
| Question | Ordering a familiar round number | Calculating the replenishment quantity |
|---|---|---|
| Does the order reflect current opening stock? | Not necessarily, since a round number is chosen independently of it | Yes, opening stock is subtracted directly from the target |
| What happens if opening stock happens to be higher than usual? | The round number is ordered anyway, creating excess stock | The calculated quantity is automatically smaller, avoiding excess |
| What happens if opening stock happens to be lower than usual? | The round number is ordered anyway, which may now be too small | The calculated quantity is automatically larger, avoiding a stockout |
Cedar & Co. calculates the target stock level from its own weekly sales rate, then subtracts opening stock.
A common mistake is reordering the same round quantity used in a previous cycle, without recalculating against this cycle's own opening stock. If Cedar & Co. had simply reordered 1,200 pieces, the full target level, without subtracting the 280 pieces already on hand, the order would have created 280 pieces of excess stock beyond real expected demand for the cycle, tying up money that a correctly calculated 920-piece order would not have. This trap is easy to fall into precisely because the round number feels safe and familiar, while the subtraction step feels like an extra piece of arithmetic that a busy buyer skips under time pressure.
Once a style reaches its reorder point, the next question is exactly how many pieces to order, not simply that an order is due. The right quantity is a target stock level, enough to cover expected sales for the coming cycle, minus whatever stock is already on hand. Skipping the subtraction and ordering the full target level, or a familiar round number instead of the calculated figure, creates excess stock: pieces beyond real demand that tie up money until they are eventually cleared. Recalculating the quantity every cycle, using the real current opening stock, keeps the order sized to real demand.
Cedar & Co.'s buyer is about to place the T-shirt style's replenishment order for the coming 4-week cycle.
Should Cedar & Co.'s buyer place the already-prepared 920-piece order, or recalculate the quantity against the new 430-piece opening stock? Decide before you open the answer.
Recalculate against the new 430-piece opening stock. The target stock level of 1,200 pieces has not changed, but opening stock has risen by 150 pieces, so the correct replenishment quantity falls to 1,200 − 430 = 770 pieces, not the already-prepared 920 pieces.
First, why placing the original 920-piece order would create excess stock. Ordering 920 pieces on top of the now-higher 430-piece opening stock would bring total stock to 1,350 pieces, 150 pieces beyond the 1,200-piece target, exactly the size of the returned batch that was not accounted for.
Second, why recalculating takes only a moment against the value it protects. Updating the opening stock figure before finalizing the order costs no more time than placing the order itself, and directly avoids 150 pieces of excess stock.
Cedar & Co.'s buyer should place a 770-piece order, recalculated against the current 430-piece opening stock, rather than the original 920-piece figure. Lesson 2.4 covers what changes when real sales themselves run faster or slower than planned.
Framed in tied-up money rather than a single penalty figure: the 150-piece difference is stock beyond real target demand.
Placing the outdated 920-piece order ties up approximately USD 480 in buying cost immediately, and risks a further USD 597 in markdown value if the 150-piece excess must later be cleared at a reduced price, all avoidable by recalculating against the current opening stock before ordering.
The workbook's "Replenishment quantity" sheet takes the style's own weekly sales rate, the replenishment cycle length, and the current opening stock, calculates the target stock level, and subtracts opening stock to give the replenishment quantity automatically.
Cedar & Co.'s own row records the 300-piece weekly rate, the 4-week cycle, and the current 430-piece opening stock, with the sheet calculating the 770-piece replenishment quantity once the opening stock figure is updated.
1. What is the correct formula for a replenishment quantity?
2. A style has a 250-piece weekly sales rate, a 3-week replenishment cycle, and 200 pieces of opening stock. What is the replenishment quantity?
3. Why must opening stock be updated to its current figure before calculating a replenishment quantity?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Replenishment cycle | دورة تجديد المخزون | Cycle de réassort | Yeniden stoklama döngüsü | One repeating round of Make to Stock production, run against a forecast rather than a single confirmed order. |
| Weekly sales rate | معدل المبيعات الأسبوعي | Taux de vente hebdomadaire | Haftalık satış oranı | The average number of pieces of a style sold in one week, found by dividing total pieces sold by the number of weeks elapsed. |
| Opening stock | المخزون الافتتاحي | Stock d'ouverture | Açılış stoku | The stock a retailer holds at the very start of a given week, before that week's own intake or sales are counted. |
| Intake | الوارد | Arrivage | Mal girişi (intake) | New stock arriving into a retailer's own stockroom or distribution centre in a given week, from a confirmed order. |
| Excess stock | المخزون الفائض | Stock excédentaire | Fazla stok | Stock ordered beyond real expected demand, left unsold and tying up money until it is cleared, often at a markdown. |
| Reorder point | نقطة إعادة الطلب | Point de recommande | Yeniden sipariş noktası | The quantity of stock remaining at which a Make to Stock buyer places its next production order against the standing forecast. |
You now know how to calculate a replenishment quantity that avoids excess stock. The next lesson covers what changes when a style's real sales run faster or slower than the rate this calculation assumed. Back to the course map