Inventory Carrying Cost Calculator
Work out what your stock costs to hold for a year, in currency and as a rate. See which component dominates, and price one extra month of cover.
Calculate Your Carrying Cost
Enter each component as a percentage of inventory value or an amount. Everything runs in your browser; no data leaves this page.
Value stock at cost, not retail. Pick-and-pack fees are fulfilment cost, not carrying cost.
Where the cost comes from
- Capital
- Storage
- Service
- Risk
| Component | Annual cost | Percent of inventory value | Share of carrying cost |
|---|
Cost of one extra month of cover
Price ordering three months instead of two, or adding a month of buffer.
Enter a monthly cost of goods sold to price an extra month of cover.
What Carrying Cost Is Made Of
Four components, always the same four, roughly in the order they get forgotten.
Capital
Money in stock is money doing nothing else. No invoice arrives for it, which is why it is missed.
Storage
Rent or 3PL fees for the space the stock occupies, plus the handling holding it causes.
Service
Insurance on stored goods, plus any inventory or property tax that applies where the stock sits.
Risk
Obsolescence, shrinkage, damage and markdown. This is what separates honest models from flattering ones.
| Component | What it covers | Where your number comes from | How it usually goes wrong |
|---|---|---|---|
| Capital cost | The money tied up in stock that has not sold yet. | Your cost of capital, or the return the cash would earn elsewhere. | Left out entirely, because no invoice arrives for it. |
| Storage cost | Warehouse rent or 3PL storage fees, racking, utilities and handling. | Your lease, or storage lines on twelve months of 3PL invoices. | Counted at the contracted rate, not the rate billed after surcharges. |
| Service cost | Insurance on stored goods, plus any inventory or property tax. | Your insurance schedule and any tax assessment on the stock. | Assumed trivial without being measured against inventory value. |
| Risk cost | Obsolescence, shrinkage, damage, and markdowns to clear ageing stock. | Your write-off ledger, cycle-count variances and markdown history. | Treated as a bad quarter, not a recurring measurable rate. |
Every Calculation on This Page
Each output above comes from one of these lines, rounded once at the end.
| Output | Formula | Note |
|---|---|---|
| Capital cost | Average inventory value × capital rate | Or enter the annual amount if finance already tracks it. |
| Storage cost | Annual storage spend, or rate × volume held × 12 | Monthly figures are multiplied by 12 first. |
| Service cost | Average inventory value × service rate | Insurance and inventory tax, as a rate or an amount. |
| Risk cost | Average inventory value × risk rate | Obsolescence, shrinkage, damage and markdown in one rate. |
| Total annual carrying cost | Capital + storage + service + risk | Everything below is derived from this figure. |
| Carrying cost rate | Total annual carrying cost ÷ average inventory value × 100 | The percentage that feeds EOQ and every stock-level argument. |
| Cost per month | Total annual carrying cost ÷ 12 | For decisions measured in weeks, not years. |
| Cost per unit per year | Total annual carrying cost ÷ average units held | This is H in EOQ. Shown only if you enter units held. |
| Component share | One component ÷ total annual carrying cost × 100 | Shows which component decides the answer. |
| One extra month, buffer | Monthly cost of goods sold × carrying cost rate | A permanent extra month is carried all year. |
| One extra month, cycle stock | Monthly cost of goods sold ÷ 2 × carrying cost rate | A bigger order raises average stock by half the extra. |
Percentages and amounts must not double up
Each component is counted once, in whichever form you chose. If finance already gives you an annual capital charge, switch that component to an amount instead of entering a rate.
A US Seller, Start to Finish
A homewares brand holds stock in a US 3PL warehouse and sells across the US. These figures are loaded above.
| Input | Value | How it was built |
|---|---|---|
| Average inventory value | USD 480,000 | Average of twelve month-end stock valuations at cost. |
| Average units held | 32,000 units | Same twelve month-ends, so the average unit cost is USD 15. |
| Cost of capital | 9% per year | The rate finance uses for working capital tied up in stock. |
| Storage | USD 3,200 per month | Storage lines on twelve months of 3PL invoices, surcharges included. |
| Service | 0.6% per year | Insurance premium on stored goods against average inventory value. |
| Risk | 4.5% per year | Write-offs, cycle-count shrinkage and clearance markdown over the year. |
| Monthly cost of goods sold | USD 240,000 | Annual cost of goods sold of USD 2,880,000, divided by twelve. |
| Component | Arithmetic | Annual cost | Share of total |
|---|---|---|---|
| Capital | 480,000 × 9% | USD 43,200 | 40.7% |
| Storage | 3,200 × 12 | USD 38,400 | 36.2% |
| Service | 480,000 × 0.6% | USD 2,880 | 2.7% |
| Risk | 480,000 × 4.5% | USD 21,600 | 20.4% |
| Total | 43,200 + 38,400 + 2,880 + 21,600 | USD 106,080 | 100.0% |
The result
Carrying cost rate = 106,080 ÷ 480,000 × 100 = 22.1% a year. That is USD 8,840 a month, and USD 3.32 per unit per year across 32,000 units.
Cover is 480,000 ÷ 240,000 = 2.0 months. One extra month as permanent buffer costs 240,000 × 22.1% = USD 53,040 a year. As a bigger order cycle, average stock rises half a month, so USD 26,520.
Capital and storage are 77% of the total here. Any serious attempt to cut it has to touch one of those two, not the 2.7% insurance line.
Where Each Number Actually Comes From
Wrong rates come from a wrong base or a missing component. Here is the source for each field.
| Input | How to build it | What to watch |
|---|---|---|
| Average inventory value | Average closing stock value at cost across twelve month-ends. | Use cost, not retail. A retail base inflates every output. |
| Average units held | Average the closing unit count across the same month-ends. | Meaningful only for one SKU or a uniform range. |
| Capital rate | Your borrowing rate, or the return that cash would earn elsewhere. | A blended debt and equity rate is normal. Finance owns it. |
| Storage spend | Twelve months of storage lines, including surcharges billed. | Pick-and-pack fees are fulfilment, not holding. |
| Service rate | Annual insurance premium on stock, plus inventory or property tax. | Check whether the premium also covers stock in transit. |
| Risk rate | Write-offs, markdowns and shrinkage, against average value. | A rate of zero says the stock never ages. |
| Monthly cost of goods sold | Annual cost of goods sold at cost, divided by twelve. | Needed only for the extra-month-of-cover panel. |
Storage and risk are not linear in time
Third-party warehouse contracts commonly escalate storage rates for stock sitting beyond a set period, and obsolescence risk climbs as stock ages. Read your own contract for the thresholds, as these terms are negotiated per account.
Use the rate actually billed over the last twelve months, not the rate card.
Why There Is No Typical Rate Here
Articles often quote a standard carrying cost range. We do not publish one.
What a borrowed range cannot know
- Your cost of capital, which alone can swing the total by ten points.
- Your storage rates, which differ by market, contract and dwell.
- Your obsolescence profile, nothing alike for consumables and electronics.
- Whether stock sits in one pooled location or several markets.
- Whether you hold cycle stock only, or a large permanent buffer too.
- Which components the quoted range included, since it rarely says.
The rate you can defend is the one you built
A rate built from your own capital rate, storage invoices and write-off ledger survives a conversation with finance. A number from an article will not, and it sets every order quantity you place.
Bigger Orders Are Not Automatically Cheaper
Ordering less often cuts ordering and freight cost, and raises carrying cost. The table works both sides.
Annual demand 96,000 units at USD 30, ordering cost USD 4,500 per replenishment, rate 22.1%. Average cycle stock is half the order quantity.
| Order quantity | Orders per year | Annual ordering cost | Average cycle stock value | Annual carrying cost | Total annual cost |
|---|---|---|---|---|---|
| 8,000 units | 12.00 | USD 54,000 | USD 120,000 | USD 26,520 | USD 80,520 |
| 11,416 units | 8.41 | USD 37,842 | USD 171,240 | USD 37,844 | USD 75,686 |
| 16,000 units | 6.00 | USD 27,000 | USD 240,000 | USD 53,040 | USD 80,040 |
| 24,000 units | 4.00 | USD 18,000 | USD 360,000 | USD 79,560 | USD 97,560 |
What the supplier discount has to beat
Moving from 16,000 units to 24,000 adds USD 17,520 a year, or USD 0.18 across 96,000 units. A volume discount at the larger break must exceed 0.61% of the USD 30 unit cost to break even.
The 11,416-unit row is the economic order quantity for these figures, where the two costs meet.
One Blended Rate Hides the Expensive Tail
Carrying cost accrues with time, not sales, so one rate lands very differently by SKU.
Carrying cost per unit sold = unit cost × rate ÷ inventory turns. Shown for a USD 30 unit at 22.1%.
| Inventory turns | Cover held | Carrying cost per unit sold | Share of unit cost |
|---|---|---|---|
| 12 turns a year | About 1 month | USD 0.55 | 1.8% |
| 6 turns a year | About 2 months | USD 1.11 | 3.7% |
| 3 turns a year | About 4 months | USD 2.21 | 7.4% |
| 1.5 turns a year | About 8 months | USD 4.42 | 14.7% |
| 0.75 turns a year | About 16 months | USD 8.84 | 29.5% |
How to use this by SKU
- Apply one carrying cost rate, divided by each SKU's own turns.
- Rank SKUs by carrying cost per unit sold, not by total inventory value.
- Compare that against the gross margin the SKU earns per unit.
- Flag anything where carrying cost passes a quarter of unit cost.
- Re-run after every promotion, because turns move and cost follows.
What Actually Lowers Carrying Cost
Every lever has a cost on the other side. The point is not to minimise carrying cost, but to see what your stock position is costing you.
| Lever | What it does to carrying cost | What it costs you instead |
|---|---|---|
| Cut the slowest tail | Removes units with the highest cost per unit sold. | One markdown now instead of a rate paid every year. |
| Order more often, smaller | Lowers average cycle stock, so capital and storage fall. | Ordering and inbound freight cost rises. |
| Shorten supplier lead time | Less cover needed for the same service level. | Usually a higher unit price or a dearer supplier. |
| Improve forecast accuracy | Lower demand variability means a smaller safety stock. | Planning time, and data you may not have. |
| Consolidate storage locations | One pooled buffer is smaller than several separate ones. | Longer delivery times to the markets you left. |
| Renegotiate the capital rate | Cheaper financing lowers the largest component for most sellers. | Finance decides it, but operations feels it. |
Safety stock is carried all year
Cycle stock averages down between deliveries, so a 16,000-unit order holds 8,000 on average. A safety buffer never averages down: every unit pays the full rate for twelve months. Weigh that against the stockout it prevents.
Where This Number Gets Used
Carrying cost feeds almost every stock decision. These tools consume it.
Carrying cost is the H in EOQ
EOQ divides by holding cost per unit per year, under a square root. That is the per-unit figure this page produces.
In the worked example it is USD 3.32 per unit. Understate it as USD 1.50 and the order quantity comes out about 49% larger.
The order quantity you place is only as good as the rate behind it.
Inventory Carrying Cost Questions
Paying Too Much to Hold Stock?
Talk to Locad about warehousing and fulfilment for your stock.