MOQ vs EOQ: what to order when the minimum is too high
Put a yearly dollar cost on a supplier minimum above your EOQ, check whether its price break pays, and use the number to negotiate a smaller lot.
MOQ vs EOQ comes down to one rule: order the larger of the two. The MOQ is your supplier's floor, and the EOQ is the lot that costs you least to order and hold. When the minimum sits far above your EOQ, put a yearly dollar figure on the gap, check whether the supplier's price break pays for it, and use that figure to ask for a smaller lot, a lower price or scheduled releases.
What is the difference between MOQ and EOQ?
Your supplier sets the MOQ: the smallest lot it will sell. You set the EOQ: the lot that keeps your yearly ordering and holding cost lowest. The two answer different questions, so they seldom match, and the higher of the two decides what you can order. When the MOQ wins, its extra stock has a yearly cost you can price.
MOQ vs EOQ at a glance
A three-column comparison of MOQ and EOQ. The supplier sets the MOQ to cover its setup and handling, and you can change it only by negotiating or switching supplier. You set the EOQ from annual demand, the cost of one PO and the cost of holding a unit for a year, and it moves when those inputs move. When the two differ, you order the larger and put a yearly cost on the gap.
| Question | MOQ | EOQ |
|---|---|---|
| Who sets it | The supplier | You |
| What drives it | The supplier's setup, tooling, packaging and handling cost per order | Your annual demand, the cost of one PO, and the yearly cost of holding a unit |
| How it changes | By negotiation, or by moving to another supplier | When demand, price or your order cost changes |
| When the two differ | If the MOQ is higher, order the MOQ: the supplier sells no less | If the EOQ is higher, order the EOQ in whole packs |
Your supplier sets the MOQ and you set the EOQ. Order the larger and put a yearly price on the gap.
Your supplier sets a minimum to cover a setup, tooling, packaging or a pick, which it pays once per order whatever you buy. Your EOQ answers how big a lot keeps your own ordering and holding cost lowest. Both numbers are right for the company that set them.
What should you order when the MOQ is above your EOQ?
Order the MOQ, unless its yearly cost is high enough to ask the supplier for other terms. You can still place the order. Each lot costs you more to hold than it saves you in orders, and you weigh that difference against what the supplier offers.
Work it the same way each time:
- Work out your EOQ.
- Cost a year at the MOQ and at each price break the supplier quotes, including the purchase cost.
- Compare the totals. The gap between the cheapest lot the supplier accepts and your EOQ is your budget for negotiating.
The EOQ calculator runs these steps on your own numbers, and its free spreadsheet template does the same in Excel or Google Sheets.
Set one objective before you size the lot
Pick what you are minimising before you compare lots: the least inventory for a service floor, the most service for a budget, or the least total relevant cost. For one purchased part, the last is the plainest to work with. Total relevant cost has four parts:
- Holding: inventory value × carrying rate.
- Ordering and receiving: orders a year × cost per order.
- Expediting: what you pay to pull late orders in.
- Shortage: expected units short × what each missed unit costs you.
The MOQ moves the first two: fewer orders, more stock. The safety stock you hold on top moves the last two, and a big MOQ changes how you should set it.
How do you calculate EOQ for a purchased component?
EOQ = √(2 × D × S / H). D is the units you use a year. S is what you spend to place, receive and pay one PO. H is what you spend to hold one unit for a year: the unit price times your carrying rate. Total yearly cost adds purchase to ordering and holding.
- Total annual cost = (D / Q) × S + (Q / 2) × H + D × unit price
- H = unit price × carrying rate
Take a die-cast housing as an illustrative example. You use 2,400 a year, a PO costs you $60, and the supplier charges $4.00 with an MOQ of 5,000. At a 25% carrying rate, H is $1.00 a year. Carrying rates commonly run 20% to 30% a year, covering capital, storage, insurance and tax, shrink and obsolescence, so 25% is a planning assumption inside that range. Correct it with the write-offs you record each year.
EOQ = √(2 × 2,400 × $60 / $1.00) = 537 units. At that lot you spend 2,400 / 537 × $60 = $268 a year on ordering and 537 / 2 × $1.00 = $268 on holding, $537 together. At the EOQ, ordering and holding cost the same.
What does an MOQ above your need cost you?
You pay for extra holding, keep more cash on the shelf, and risk a larger write-off when the part changes. For the housing, the 5,000 MOQ covers 25 months of use. Ordering falls to $29 a year and holding rises to $2,500, so you pay $1,992 a year more than at the EOQ, before any scrap.
- Months of supply: 5,000 / 200 a month = 25 months per lot.
- Yearly penalty: (2,400 / 5,000 × $60) + (5,000 / 2 × $1.00) = $2,529, against $537 at the EOQ. The difference is $1,992 a year.
- Cash: you hold $10,000 on average and pay $20,000 per PO, against $1,073 and $2,147 at the EOQ.
- Scrap exposure: if engineering revises the housing after 12 months, you hold about 2,600 units, about $10,400 at $4.00.
Screen your parts: count the ones whose MOQ covers more than a year of demand, or 6 or 3 months for parts that change often. Rank that list by yearly penalty and scrap exposure to pick where to start. Parts already over the line go into your excess and obsolete inventory review.
Does a price break at the MOQ pay for the extra stock?
It pays when the yearly saving on purchase cost beats the extra holding. You find out by costing the whole year. A lower price cuts both purchase and holding cost per unit, yet a lot many times your EOQ can cost more in total than a smaller lot at the higher price.
Say the supplier quotes $3.60 at 5,000. Purchase falls to 2,400 × $3.60 = $8,640, ordering stays at $29, and holding comes to 2,500 × $0.90 = $2,250. You pay $10,919 a year, against $10,137 at the EOQ and $4.00. The break costs you $782 a year more, before you count the scrap risk.
Annual cost of four ways to buy one component
An illustrative table comparing four ways to buy a component used at 2,400 a year with a $60 order cost and a 25% carrying rate. The EOQ of 537 at $4.00 costs $10,137 a year. The MOQ of 5,000 at $4.00 costs $12,129. The MOQ of 5,000 at the $3.60 break costs $10,919. A blanket PO for 5,000 at $3.60 released in lots of 1,250 costs $9,318, the lowest of the four.
| Option | Lot received | Unit price | Ordering + holding a year | Purchase a year | Total a year |
|---|---|---|---|---|---|
| EOQ, if the supplier would sell it | 537 | $4.00 | $537 | $9,600 | $10,137 |
| MOQ at the base price | 5,000 | $4.00 | $2,529 | $9,600 | $12,129 |
| MOQ at the $3.60 break | 5,000 | $3.60 | $2,279 | $8,640 | $10,919 |
| Blanket PO for 5,000 at $3.60, released 1,250 at a time | 1,250 | $3.60 | $678 | $8,640 | $9,318 |
Illustrative example. The price break on its own costs more than the EOQ. The same break taken as scheduled releases costs less.
Work out the break-even price: the unit price at which the MOQ costs you the same per year as the EOQ.
- Break-even price = (EOQ total − D / MOQ × S) / (D + MOQ / 2 × carrying rate)
- For the housing: ($10,137 − $29) / (2,400 + 5,000 / 2 × 0.25) = $3.34, a 16.5% discount.
At $3.34 or below, the full lot pays for itself. Above it, you save by ordering less at the higher price, if the supplier will sell a smaller lot.
How does a big MOQ change your safety stock?
A big lot covers most replenishment cycles by itself, so a cycle-service target overstocks it. When the MOQ is large next to the variability of demand over the lead time (σLTD), set safety stock by fill rate, the share of demand you serve from stock, and label every service figure with its type.
For parts with a small MOQ, the safety stock calculator sizes the buffer from the supplier's lead-time spread.
- Cycle service level (alpha): the chance of no stockout in one replenishment cycle. Safety stock = z × σLTD.
- Fill rate (beta): the share of demand served from stock. It depends on the lot size Q: solve G(k) = (Q / σLTD) × (1 − β) for the safety factor k, then safety stock = k × σLTD.
The two can sit far apart: on lumpy demand, a 95% cycle service level can come with a fill rate of about 50%. With a 5,000 lot on 2,400 a year, the housing is short at most once every two years, so a fill-rate target needs far less buffer than a 95% cycle target.
How do you get a smaller lot or a better price?
Offer your supplier something that covers the cost its minimum protects: a firm commitment, fewer setups or a schedule it can plan around. Each option below cuts your holding cost a different way. Put a dollar figure on each one before you call, so you know which to lead with and how far you can move on price.
Scheduled releases against a blanket PO
Commit to the full 5,000 at $3.60, released in four lots of 1,250. Your supplier keeps the volume and runs one setup, and you hold a quarter of the stock. For the housing you pay $9,318 a year, less than the EOQ at $4.00. Each release has to land on time, so track releases like any open line (see purchase order tracking).
Pay more per unit for a smaller lot
For the housing, you can pay up to $4.32 for a lot of 537 and still spend less per year than on 5,000 at $3.60. Against 5,000 at $4.00, the ceiling is $4.81. The ceiling is (MOQ total − D ÷ lot × S) ÷ (D + lot ÷ 2 × carrying rate): ($10,919 − $268) ÷ (2,400 + 67) = $4.32. Use that ceiling as your walk-away price for a half or a quarter lot.
An MOQ by value across several parts
If you buy several parts from one supplier, ask it to count the minimum in dollars across the whole order. Combine parts that share a material or a setup, and add parts you will use within your screen period.
Combine the parents that use the part
A housing in three assemblies needs one demand figure. Add its use across every parent before you compare it with the MOQ, and the gap may shrink.
Ask the supplier to hold stock
Your supplier makes the full lot and ships to you on call, or holds it on consignment. Agree in writing who owns the stock, for how long, and who pays for it if you revise the part.
Move to a standard part or another supplier
If a custom feature drives the minimum, check whether a catalogue part would do. If another supplier sells the same part in smaller lots, add its price to your comparison.
Negotiation lines you can copy
Each line asks for one thing, offers one in return, and quotes a number from your own calculation. Swap in your figures.
- Scheduled releases: "We can commit to 5,000 at $3.60 on a blanket PO for the next 24 months if you ship 1,250 at a time against our releases. Can you hold the price on that basis?"
- Smaller lot at a higher price: "We use about 2,400 a year, so 5,000 is two years of stock for us. What would 1,250 cost? At up to $4.10 a unit we can place it this week."
- MOQ by value: "We buy four parts from you. Would you take a minimum of $8,000 per order across all four instead of 5,000 pieces of each?"
- Commitment for a lower MOQ: "We expect to buy around 2,400 a year for the next two years. If we sign an annual agreement for that volume, can you drop the per-order minimum to 1,000?"
- Revision risk: "This part may change revision within a year. If we order the full 5,000, will you take back unopened packs, or hold the balance until we call it off?"
Keep your numbers open during the call. Check any price the supplier offers against your break-even price and your walk-away price before you agree. Record the agreed MOQ, breaks and release terms against the supplier on your supplier scorecard, so the next buyer starts from them.
When is EOQ the wrong tool for a component?
EOQ assumes steady demand, a fixed price and a fixed lead time. It fits parts you use all year at an even rate. Look elsewhere when a build plan makes demand jump week to week, when engineering is about to change the part, or when several parts share one shipment or one minimum.
- Lumpy, build-driven demand: let MRP size each order against real requirements, with the MOQ as a lot rule. See material requirements planning.
- A part near end of life or revision: cap the lot at what you will use before the change, whatever the formula says.
- Shared freight or a shared minimum: size the combined order.
- Unreliable lead time: running short costs you more than a lot size off the optimum. See supplier lead time.
- A price about to rise: buying ahead is a separate decision, with its own carrying cost against the price rise.
Questions buyers ask
How many months of supply is too many for one lot?
No standard sets a limit. Count the parts whose MOQ covers more than 12 months of use, or 6 for parts that change often, then rank them by yearly penalty and scrap exposure.
Can a supplier's MOQ be counted in dollars instead of units?
Yes, if your supplier agrees. Many distributors set minimums by order value already. Ask for it when you buy several parts from the same supplier.
How do you handle one MOQ across several parts from the same supplier?
Cost the combined order. The parts share one order cost, so each part's own EOQ comes out too small. Fill the minimum with parts you will use within your screen period.
Why do suppliers set an MOQ?
Each order costs the supplier a setup, tooling time, packaging and a pick, whatever the quantity. The minimum makes sure each order covers those fixed costs. So cutting the supplier's setups or giving it a schedule works better than asking for less.
What can you offer a supplier to lower its MOQ?
A firm yearly commitment, scheduled releases against one blanket PO, a minimum counted in dollars across several parts, or a higher unit price for a smaller lot. Work out each one in dollars first, so you know your walk-away price.
How do you count scrap risk in an MOQ decision?
Estimate how many months of the lot you will use before the part could change, and multiply the units left at that point by the unit price. For the housing, a revision after 12 months leaves about 2,600 units, or $10,400 at $4.00.
What if MRP drives the part's demand?
Then EOQ is a rough guide at best. Let your MRP run size each order against real requirements, with the supplier's MOQ and pack size as the lot rule, and use the yearly penalty only to decide whether to negotiate the minimum.
How often should you revisit a supplier's MOQ?
Revisit it when your usage changes, when the supplier changes price, and at least once a year. A minimum that fit at 10,000 a year can be two years of stock today.
If your team spends its days following up on blanket releases and open POs, get Cartograph free. Scout Agent emails and calls your suppliers to confirm and expedite each release, so each smaller lot lands before the last one runs out.