Skip to content
OneKitly
Sign up · Sign in

Economic order quantity (EOQ) calculator

Compute the order quantity that minimizes total inventory cost.

Related tools

All Planning & operations tools →
Takt time calculatorCompute the takt time — the pace of production needed to meet demand.Double declining depreciation calculatorCompute the first-year double-declining-balance depreciation of an asset.Reorder point calculatorFind the inventory level at which to reorder, from demand, lead time and safety stock.Safety stock calculatorThe buffer inventory that protects against stockouts when demand or lead time varies: SS = Z·√(LT·σ_d² + d²·σ_LT²), where Z comes from your target service level. Enter demand, lead time and their variability, and it returns the safety stock and the reorder point.Sell-through rate calculatorCompute the sell-through rate — the share of received stock that sold.GMROI calculatorCompute gross margin return on inventory investment.Straight-line depreciation calculatorCompute the yearly straight-line depreciation of an asset.Cost of goods sold (COGS) calculatorCompute cost of goods sold from beginning inventory, purchases and ending inventory.

The Economic order quantity (EOQ) calculator turns Annual demand (units), Cost per order, Holding cost per unit/year into Economic order quantity, instantly and for free. For instance, with Annual demand (units) = 10,000, Cost per order = $50.00 and Holding cost per unit/year = $2.00 it returns Economic order quantity = 707.

How to use it

  1. Enter your values: Annual demand (units), Cost per order, Holding cost per unit/year.
  2. Read the result instantly: Economic order quantity.

Frequently asked questions

How does the Economic order quantity (EOQ) calculator work?

It takes Annual demand (units), Cost per order and Holding cost per unit/year and derives Economic order quantity from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

3 values: Annual demand (units), Cost per order ($) and Holding cost per unit/year ($). Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Annual demand (units) = 10,000, Cost per order = $50.00 and Holding cost per unit/year = $2.00, the calculator returns Economic order quantity = 707. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

How much does the result change with different inputs?

It moves a lot. Using Annual demand (units) = 20,000, Cost per order = $100.00 and Holding cost per unit/year = $4.00 instead, Economic order quantity goes from 707 to 1,000 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Annual demand (units) = 5,000, Cost per order = $25.00 and Holding cost per unit/year = $1.00, Economic order quantity comes out at 500. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Running the week: issuing an invoice or a quote, knowing what is in stock and what to reorder, and seeing whether cash covers what is due.

What is the most common mistake?

Reading profit as cash. A profitable month with sixty-day payment terms can still leave the account empty — the two numbers answer different questions.

What is the difference between the Economic order quantity (EOQ) calculator and the Takt time calculator?

This one returns Economic order quantity; the Takt time calculator returns Takt time (minutes/unit). That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Double declining depreciation calculator is the closest one after this: Compute the first-year double-declining-balance depreciation of an asset.

What else is worth having open alongside it?

Reorder point calculator and Safety stock calculator — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
ExplainerThe EOQ Square-Root Formula, and Where It Stops Being TrueEOQ = √(2DS/H) balances ordering cost against holding cost. Its most useful property is how flat the cost curve is around the optimum — and its four failure modes are quantity discounts, lumpy demand, a finite replenishment rate, and the two inputs nobody can measure.ExplainerGMROI: the Inventory Number That Outranks MarginGross margin return on inventory investment divides gross margin by the cash tied up in stock. It exists because margin alone ranks products wrongly: a 60% margin turning twice a year loses to a 25% margin turning twelve times.ComparisonStraight-Line vs Declining-Balance DepreciationBoth methods write off exactly the same total cost. Only the timing differs — and timing is worth money. A full year-by-year schedule for one asset, the crossover year, the switch-to-straight-line convention, and the present value of the tax deferral computed at 8%.ComparisonThree Schedules for One Machine: Straight Line, Declining Balance, Units of ProductionA $50,000 machine with a $5,000 salvage value and a five-year life. Straight line deducts $9,000 in year one, double declining balance $20,000, and MACRS $10,000. The lifetime total is the same; only the timing moves — and the timing is worth about $320.ExplainerProcess Capability: Cp, Cpk and What Six Sigma Actually ClaimsCp compares the spec width to the process spread; Cpk penalises being off-centre. A process can have an excellent Cp and still make scrap — here is the case, with defect rates computed from the normal distribution rather than read off a table.ExplainerTakt Time, Cycle Time and Lead Time Are Three Different ClocksTakt is demand, cycle time is capability, lead time is what the customer experiences. Confusing them is the most common failure in a first improvement project — and Little's Law is the bridge from one to the next.