Inventory carrying cost calculator
A distributor holding $500,000 of stock spends $131,000 a year to hold it: $50,000 for the cash tied up at 10%, $32,000 of storage, $13,000 of insurance, tax and systems, and $36,000 of shrinkage and write-offs. That is a carrying cost rate of 26.2%. But only $101,800 of it would fall if the company held less. Cut the stock by 20% and the saving is $20,360 a year, not the $26,200 that the flat rate promises. An item with a 20% gross margin stops earning anything after 11.5 months on the shelf.
The calculator builds the rate from your own capital, storage, service and risk costs, splits it into avoidable and fixed cost, and turns it into a cost per unit, a cost per month and the number of months a product can sit before holding it costs more than it earns.
Your inventory
What holding it costs each year
Take storage, service and risk from your books. Capital is a rate on the stock.
How much of each falls if you hold less stock
Fixed costs such as a lease do not shrink with the stock unless you give the space back.
One product, and a cut to test
The starting values are illustrations of a distributor with $500,000 of stock. Replace them with your own.
Carrying cost rate
26.2%
Cost of holding it a year
$131,000
Avoidable rate
20.4%
Per unit, per month
$0.44
Where the $131,000 goes
Holding this stock costs 4.4% of cost of goods sold and 3.5% of revenue. It turns 6.0 times a year, 61 days of stock. $29,200 of the cost is fixed and does not fall if you carry less.
What a cut of 20% would really save
Cash released
$100,000
Carrying cost saved, avoidable costs only20.4% × $100,000
$20,360 a year
What a flat 26.2% rate would claimOverstates the saving by 29%.
$26,200 a year
Each day of inventory you removeOne day of cost of goods sold is $8,219 of stock.
$1,673 a year
One product: how long it can sit
Carrying cost per unit, a year and a month
$5.24 · $0.44
Margin per unit$25.00 price − $20.00 cost = 20% gross margin
$5.00
Months on the shelf that erase the marginBeyond this the unit loses money once holding costs are counted.
11.5 months
| Gross margin | Months until holding cost erases it |
|---|---|
| 20% | 11.5 |
| 30% | 19.6 |
| 40% | 30.5 |
| 50% | 45.8 |
If the cost of capital were different
| Capital rate | Carrying cost | Rate on the stock |
|---|---|---|
| 4% | $101,000 | 20.2% |
| 6% | $111,000 | 22.2% |
| 8% | $121,000 | 24.2% |
| 10% | $131,000 | 26.2% |
| 12% | $141,000 | 28.2% |
| 14% | $151,000 | 30.2% |
The rate is only as good as the figures behind it. Ordering and setup costs belong in an order-quantity model and are not included here. The avoidable shares are judgments to check against your leases, contracts and insurance terms. Published ranges such as “20% to 30%” are unsourced rules of thumb. Not financial or accounting advice.
A carrying cost workbook: a ledger sheet where each holding cost gets an annual total, the share attributable to inventory and a category, feeding the four buckets. It shows the rate, the avoidable rate, the cost per unit, the months to erase a margin, the value of a cut and a sensitivity to the cost of capital. Every formula is editable, and the starting values are illustrations.
Download the workbookWho reaches for this
Wants to know what the warehouse of stock costs to carry, and which part of that cost a smaller warehouse would remove.
Wants to see how long a slow product can sit before it stops making money.
Wants the carrying cost of raw materials and finished goods for an order-size decision.
Wants a rate built from the ledger, to replace the 20% or 25% that everyone assumes.
Wants the cost of holding it against the discount for buying in bulk.
How this inventory carrying cost calculator works
You enter the average value of the stock at cost, the year’s cost of goods sold and revenue, and the cost of the cash tied up in the stock. Storage, service and risk are annual dollar amounts from your books. For each of the four buckets you also say what share of the cost would fall if you held less stock. The calculator adds them up, divides by the average stock and reports the rate. It also reports the avoidable rate, the cost per unit, and the cost of an extra day of inventory.
Most calculators and guides ask for a rate and multiply. This one goes the other way, so that the rate is a result and not an assumption. The days inventory outstanding calculator and the inventory turnover calculator both take a carrying rate as an input. This page is where that number comes from.
The four buckets, and what goes in each
Almost every source divides carrying cost the same way. The buckets are useful, and the trouble is that the guides give them as percentages and rarely say where the dollars come from. Here is what belongs in each and where to find it.
The cost of the money tied up in stock. It is the cost of capital or the interest on the line that funds the stock, times the average inventory. It is usually the largest bucket, and it is not on the income statement unless it is interest.
The space and the work: warehouse rent or the cost of owned space, utilities, and the handling labor and equipment used to store and move stock. Include only the share attributable to inventory, such as the part of a building the stock occupies.
Insurance on the stock, property or inventory tax where it applies, and the systems and counts that track it. Premiums and some taxes follow the value of the stock.
Shrinkage from theft, damage and error, spoilage, and write-offs and markdowns for stock that became obsolete or slow. The ledger evidence is the write-downs and the shrink adjustments after counts.
In the example, the capital bucket is 10% of $500,000, or $50,000. Storage is $32,000: half of a $48,000 warehouse lease, 40% of $10,000 of utilities, and half of $8,000 of stock-room labor. Service is $13,000: $6,000 of insurance, $4,000 of property tax and half of a $6,000 systems and counting cost. Risk is $36,000: $9,000 of shrinkage and $27,000 of obsolescence write-offs. The total is $131,000, which is 26.2% of the stock, or 4.4% of the $3 million of cost of goods sold and 3.5% of revenue.
The workbook’s ledger sheet lists each cost with the share attributable to inventory, so the allocation is visible and can be argued with. Shares such as “half the warehouse” are judgments, and writing them down is the main step toward a rate that finance and operations both accept.
Average inventory, not a single balance
The denominator is the average value of the stock over the year, not the balance on the last day. Take the average of the month-end balances, or of weekly counts if you have them. A seasonal business can have a year-end balance far from the average. If the example company happened to close the year with $380,000 of stock, dividing the same $131,000 by that figure would give 34.5% instead of 26.2%, a rate that reflects the timing of the count and says nothing about the cost of holding.
Choosing the capital rate
The capital rate is the assumption with the most effect, and the guides handle it loosely. Three choices are common.
Use the one that matches how the stock is really funded, and state it. Each point of the rate moves the total by 1% of the stock, which is $5,000 a year on $500,000. At a 4% capital rate the example’s carrying cost is $101,000, or 20.2%. At 10% it is $131,000, or 26.2%, and at 14% it is $151,000, or 30.2%. Ten points of capital rate account for the whole range that guides quote for carrying cost, so the capital rate should not be left to a default.
Cost of capital also changes over time. A rate that was 5% two years ago may be 9% now, and the same stock costs more to hold without a change in the warehouse. Revisit the rate when borrowing costs move.
The risk bucket from your write-offs
Risk is the bucket most often estimated and least often measured. It is also the most direct evidence that a business is holding stock for too long. The dollars are in the ledger: the adjustments after physical counts, the write-downs of slow and obsolete items, and the markdowns taken to clear them. Accounting rules such as IAS 2 and ASC 330 require inventory to be carried at the lower of cost and net realizable value, so a write-down is the record of stock that lost value while it was held.
In the example, $36,000 of shrinkage and write-offs against $500,000 of average stock is a risk rate of 7.2%. That is a single year, and risk is lumpy: one bad season or one discontinued product line can dominate. An average of three years gives a steadier figure. It also varies enormously by product. Fashion, electronics and food carry high risk, and fasteners and bulk chemicals carry little.
If you cannot separate shrinkage and write-offs in your books, sample them: count a category, compare it with the records, and look at what was written down last year. A rough measured figure is better than a typical range, and it points at the products where the money is being lost.
What is not carrying cost
Counting too much is as common as counting too little. Three things do not belong.
The cost of placing an order, receiving it or setting up a production run is a cost of buying, and it belongs in an order-quantity model. It moves opposite to carrying cost as the order size changes.
Lost sales and expedited freight from running out are the cost of holding too little. They belong in a service-level or safety stock decision.
The whole warehouse rent is not attributable to stock if the building also holds an office or a production line. Allocate the share the stock uses.
The line between carrying and ordering costs matters because the two are traded off. The inventory turnover calculator shows the order size that minimizes their sum, and the safety stock calculator covers the buffer against running out. Counting a cost in two of them makes every estimate wrong.
Avoidable vs fixed cost
The most useful question about carrying cost is not how much it is, but how much of it would go away. A 26.2% rate applied to $100,000 of stock removed suggests a $26,200 saving. Some of that cost does not fall.
Cost of capital and shrinkage scale with the stock. Insurance may, where premiums follow the insured value, and property tax on inventory does so in the places that levy it. A lease does not. If you cut stock by a fifth and keep the same warehouse, the rent is unchanged, and only the part you sublet, exit or avoid expanding counts. In the example, only a quarter of storage cost falls.
The avoidable rate is $101,800 ÷ $500,000 = 20.4%, against the full 26.2%. A 20% cut in stock releases $100,000 of cash and saves $20,360 a year. The flat rate says $26,200, which overstates the saving by 29%. The gap is $5,840 a year of rent and overhead that stays. The fixed $29,200 only falls when a decision, such as giving back space, removes it, and that decision can be worth making, but it is a separate one.
The avoidable shares are judgments. Check them against your lease terms, your insurance policy and how your tax authority values inventory. The calculator lets you set each one, and a sensitivity to a range of shares is easy to run.
Cost per unit and per month
A rate is abstract, and a cost per unit is not. The carrying cost of one unit is its cost times the rate. A $20 unit at 26.2% costs $5.24 a year to hold, or $0.44 a month. Applied to the whole stock, the same arithmetic gives the $131,000.
The number is useful when it is compared with something. A month of holding a $20 unit costs 44 cents, and if the unit is sold for $25 the gross margin is $5. That is about eleven months of holding cost. It is also the cost of a decision to buy more than needed: an extra thousand units held for a quarter costs $1,310, from $20,000 of stock at 26.2% for three months.
The cost of a day of inventory
The same idea works for the whole business. One day of cost of goods sold is $3,000,000 ÷ 365 = $8,219 of stock. Removing a day of inventory releases that cash once and saves the avoidable rate on it every year, 20.4% of $8,219, or $1,673. The days inventory outstanding calculator shows how to find the days in your own inventory, and this page supplies the rate.
Carrying cost in the price of a product
If a product typically sits for 90 days before it sells, it has cost 26.2% × 90 ÷ 365 = 6.5% of its purchase price to hold. On a $20 unit that is $1.29, so the true cost is $21.29. To keep a 20% gross margin on that cost the price has to be $21.29 ÷ 0.80 = $26.61, not $25. Pricing from the purchase cost alone gives the carrying cost away, and it gives away more on the products that move slowly. The markup vs. margin calculator converts between the margin you want and the markup that produces it.
How long stock can sit before margin disappears
Holding cost accumulates every month a unit is on the shelf, and the margin does not grow. Divide the margin per unit by the monthly carrying cost and you have the number of months of shelf time that erase it. Beyond that point the sale loses money once holding cost is counted.
The lower the margin, the sooner it is gone, and the effect is largest on the products that turn slowest. A distributor with a 20% margin whose stock averages 61 days is comfortable. The same distributor holding a slow line for a year has spent the entire margin on holding it. An item that sits for 23 months costs twice its margin to hold, before any markdown.
Use it as a test on the aged part of the stock. List the items that have been on hand longer than the erase point for their margin. Those are candidates to clear, return to the supplier, bundle or stop reordering. The sell-through rate calculator shows how to spot them earlier, while there is still time to sell them at full price.
What to do with the number
To value a cut in stock, multiply the cash released by the avoidable rate, not the full rate.
To cost a product, a batch or a bulk-buy discount, the full rate is the fair charge for the stock it holds.
The holding cost per unit in the economic order quantity formula is the unit cost times the rate.
Multiply each product’s average stock by the rate and compare it with its margin. The products where holding costs approach the margin are the ones to act on.
Recompute the rate each year. It moves with interest rates, write-offs and the space you rent.
A bulk-buy discount is a good test. A supplier offers 5% off for buying six months of stock at once instead of two. Each unit then sits on the shelf about two months longer on average, which costs about 2 ÷ 12 × 26.2% = 4.4% of its price to carry. The discount looks slightly better than the cost of holding it, and less good once the risk of a slower month is added. The comparison is only possible with a rate.
An annual routine
Once a year, after the year-end close, pull the ledger lines that relate to holding stock, update the allocation shares, compute the average inventory from the month-end balances, and refresh the cost of capital from your lender or your finance team. Enter them, note the rate and the avoidable rate, and compare with last year. If the rate moved, ask which bucket caused it. A rise in write-offs points at buying and forecasting, and a rise in capital cost points at the financing.
What counts as a typical rate
Guides give ranges. One says carrying costs are usually 15% to 30% of inventory value. Another says 20% to 30% across most industries, and another that a healthy rate in 2026 is 20% to 25% and that above 30% suggests too much slow stock. A fourth gives component ranges that sum to 20% to 45%: capital 8% to 15%, storage 5% to 10%, service 2% to 5% and risk 5% to 15%. Worked examples in the guides come out at 14.5%, 15%, 19.3%, 20%, 22% and 30%. I could not trace any of these ranges to a primary source.
They conflict, and they should. The rate depends on the cost of capital, on the product and on the warehouse, and the same company can move five points or more as rates or the product mix change. A distributor of durable parts and a seller of seasonal fashion are not carrying the same thing. A range is a rough check that a rate is not absurd, and it is a poor substitute for a rate built from your own figures, which is the reason to use the ledger.
Common mistakes
A 25% or 20% rate copied from a guide hides the capital rate, the write-offs and the space you use.
Fixed costs such as rent do not fall with the stock. Use the avoidable rate.
It is often the largest bucket and it is not an expense on the income statement.
Allocate only the share the inventory uses.
They belong in an order-quantity model, where they trade off against carrying cost.
Use the average over the year. A seasonal business can differ widely between the two.
Carrying cost is a percentage of the cost of the stock, not of what it sells for.
Write-offs and shrinkage are real costs of holding stock, and they grow with time on the shelf.
What this calculator can't tell you
The rate is only as good as the figures you enter. The allocation of rent and labor to inventory, the avoidable shares and the cost of capital are judgments, and the calculator applies them without checking them. It treats the costs as scaling in a straight line with the stock, and real costs come in steps: a warehouse does not shrink by a fifth when the stock does.
It does not include ordering, setup or stockout costs, or the effect of quantity discounts, which are decisions with their own models. It uses average inventory at cost and does not adjust for seasonality within the year. The example distributor is invented, and the range figures quoted from guides are rules of thumb I could not verify.
This is a planning aid, not financial or accounting advice.
Sources
The four-bucket structure, with capital, storage, service and risk costs divided by average inventory value, is standard in supply chain and inventory management texts and is used by guides from Zoho, inFlow, Cleverence, Impact Analytics and others. The range figures cited come from those guides and are presented as claims. The lower-of-cost-and-net-realizable-value measurement of inventory is set out in IAS 2 and ASC 330. The examples were computed with the same engine as the calculator and checked by hand: $131,000 ÷ $500,000 = 26.2%, and $101,800 ÷ $500,000 = 20.4%.
Frequently asked questions
Inventory carrying cost is what it costs to hold unsold stock for a year. It covers the return on the cash tied up in the stock or the interest paid to finance it, the space it occupies, insurance and taxes on it, and the losses from shrinkage, damage and obsolescence. It is usually stated as a percentage of the average value of the inventory. A distributor with $500,000 of stock and $131,000 of annual holding costs has a carrying cost of 26.2%.
Carrying cost rate = (capital cost + storage cost + service cost + risk cost) ÷ average inventory value × 100. Capital cost is the cost of money times the stock. Storage, service and risk costs come from the books. In the example, $50,000 of capital cost, $32,000 of storage, $13,000 of service and $36,000 of risk make $131,000, and $131,000 ÷ $500,000 is 26.2%. Use average inventory over the year, not a single year-end balance.
Four buckets. Capital: the cost of the money tied up. Storage: rent, utilities and handling labor for the space the stock uses. Service: insurance, property or inventory tax and the systems that track the stock. Risk: shrinkage, damage, spoilage and write-offs for goods that become obsolete. Ordering, setup and receiving costs are not carrying costs, and they belong in an order-quantity model. Stockout costs are a separate question.
Published figures range from 15% to 30%, with 20% to 30% and about 25% repeated often, and one guide adds component ranges that sum to 20% to 45%. I could not trace any of them to a source. The rate varies with the cost of capital, the product, the warehouse and the risk of obsolescence, and it can move five points as rates or the product mix change. Build your own from your books, and use the ranges as a rough check.
Multiply the unit cost by the carrying cost rate to get the cost per unit per year, then divide by 12 for a month. A $20 unit at a 26.2% rate costs $5.24 a year to hold, or $0.44 a month. A unit that sits for a year costs more than a 20% gross margin on a $25 price, which is $5. The rate applies to the cost of the unit, not to its selling price.
Most sources use the two terms for the same thing. Some reserve holding cost for the cost per unit per year used in an order-quantity model, and carrying cost for the total or the percentage. Others use carrying cost for the financial cost of the capital and holding cost for the physical costs. Check the definition each time. The calculator uses carrying cost for the total of all four buckets.
It is the holding cost in the formula. The order quantity that minimizes total cost is the square root of (2 × annual demand × ordering cost ÷ holding cost per unit per year), and the holding cost per unit is the unit cost times the carrying cost rate. A higher carrying rate lowers the best order size, so you order smaller batches more often. The inventory turnover calculator covers the order-quantity calculation.
The part that falls when you hold less stock. Cost of capital and shrinkage fall with the stock. Insurance may fall if premiums follow the insured value. Rent on a warehouse you cannot shrink does not fall unless you give space back. In the example, 26.2% is the full rate and 20.4% is the avoidable rate. A 20% cut in stock saves $20,360 a year, not the $26,200 a flat rate would claim.
Use the rate the money really costs you. If the stock is financed by a line of credit, use the interest rate on it. If it is paid for from cash, use the return you would earn on that cash elsewhere, or the return the business requires. Each point of the rate moves the carrying cost by 1% of the stock, or $5,000 a year on $500,000. Use the same rate each year and state it, so that comparisons hold.
Hold less stock or make each dollar work harder. Cut slow-moving and obsolete items first, since they carry the risk cost. Improve forecasting and lead times so that less safety stock is needed. Order in the size that balances ordering and holding costs. Give back space when the stock allows it, since rent is often the fixed part. Each day of inventory removed in the example releases $8,219 of cash and saves about $1,673 a year.
Higher turnover means the same sales are supported by less stock, so the carrying cost is a smaller share of cost of goods sold. In the example the stock turns 6.0 times a year, 60.8 days, and carrying it costs 4.4% of cost of goods sold. Doubling the turns to 12 would halve the stock and, with the same rate, roughly halve the cost. The rate on the stock stays the same, but the dollars fall.
When the time on the shelf times the monthly carrying cost equals the margin per unit. The months are margin per unit ÷ (unit cost × rate ÷ 12). At a 26.2% rate, a 20% gross margin is gone after 11.5 months, a 30% margin after 19.6 months, 40% after 30.5 and 50% after 45.8. Slow-moving items with thin margins are where holding cost turns a sale into a loss.
Find your days of stock with the days inventory outstanding calculator, or see how fast each product sells with the sell-through rate calculator.
Glossary:Inventory Carrying Cost,Carrying Cost Rate,Inventory Shrinkage,Inventory Turnover
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