Cash required to support growth at your sales velocity and lead times.
Inputs
YoY
Inventory needs
Inventory cash needed—
For current run-rate
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For 12-mo growth
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Additional cash needed
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About this calculator
Inventory is the largest working-capital line item for most ecommerce brands, and the one most operators dramatically under-plan. The formula: (lead time + safety stock) × daily COGS = baseline inventory investment needed. At typical 60-day lead times plus 30-day safety, that\'s 90 days of COGS sitting in product at any given time.
Growth multiplies the requirement. If you\'re scaling 50% year-over-year, your inventory needs scale with you — but the cash to pay for inventory must arrive 60-90 days before the revenue. This calculator quantifies the gap: current inventory cash vs what you\'ll need to support 12 months forward of growth.
The most common miss: operators size inventory for current revenue, then run out of stock 3 months later when revenue has grown 20%. Or they order based on forecast revenue but run out of cash because they didn\'t plan for the working-capital expansion. Both are fixable with proper math up front.
Inventory financing (Wayflyer, Settle, traditional revenue-based) bridges the cash-deployment-vs-revenue-arrival gap at 8-15% APR. Pair this with the Loan Repayment Calculator (to compare financing options) and the MOQ vs Cash Flow Modeler (for supplier minimum-order constraints).
Frequently asked questions
How much inventory cash do I need?
Roughly: (lead time + 30 days safety) × daily COGS. So at $2K/day COGS with 60-day lead time + 30-day safety, you need $180K in inventory. Growth requires more — if scaling 50% YoY, plan for inventory cash to grow proportionally ahead of demand.
Why does growth require more inventory cash?
Inventory funds future demand, not current. If you're selling $100K/month today and growing to $150K/month next quarter, you need inventory cash sized for the higher volume — purchased now, before the demand arrives. Many operators fund growth via outside capital because organic profit can't fund inventory ahead of demand.
When should I take inventory financing?
When inventory investment exceeds 90 days of operating profit. At that point, organic cash flow can't fund growth without starving operations. Inventory-specific financing (Wayflyer, Settle, traditional working capital) at 8-15% APR is usually cheaper than slowing growth.
What's the cost of carrying too much?
10-15% APR opportunity cost (cash that could earn elsewhere) plus 5-15% storage/obsolescence cost = 15-30% annual cost of excess inventory. Carrying $100K of unnecessary stock costs $15-30K/year — invisible on the P&L but real.
How does seasonality affect inventory cash?
Q4-heavy categories need 1.5-2× normal inventory by mid-October to support peak. That cash must be deployed in July-August (factory lead times). Operators who don't plan this run out of cash mid-Q3 or run out of inventory mid-Q4 — both kill the year.